Adarbad Mahraspandan was a famous saint, High priest, and prime minister of Shapur II (309-379 A.C.)
Translation from R. C. Zaehner, The Teachings of the Magi, London, 1956, p. 101 ff. Comments in  by JHP. Spelling has been normalized to conform with other texts in this series. I have also used 'yazads' in place of Zaehner's 'gods' which I think is very misleading. -JHP.
For a Finnish translation, see https://www.auto-onderdelenexpert.nl/blog/2017/04/03/neuvoja-adarbad-mahraspandan/.
For a Polish translation, see http://www.pkwteile.de/wissen/rad-adarbad-mahraspandan.
For a Ukranian translation, see http://eustudiesweb.com/counsels-of-adarbad-mahraspandan/.
THE COUNSELS OF ADHURBADH, SON OF MAHRASPAND
([Source for text:] Pahlavi Texts [ed. J. D. Jamasp-Asana, Bombay, 1897], pp. 58-71)
(1) It is related that Adhurbadh had no child of his body and that he thereafter put his trust in the yazads. And it was not long before a son was (born) to Adhurbadh, and because Zartosht, son of Spitam, had an upright character, he called him Zartosht (Zoroaster), and said "Arise, my son, that I may teach thee civilized behaviour (frahang).
(2) My son, think upon virtue and do not turn your thoughts to sin, for man does not live eternally and the things of the spirit are the more greatly to be desired.
(3) Put out of your mind what is past and do not fret and worry about what has not yet come to pass.
(4) Put not your trust and confidence in kings and princes.
(5) Do not do unto others what would not be good for yourself.
(6) Be single-minded among rulers and friends.
(7) Do not deliver yourself up as a slave to any man.
(8) Stay far away from any man who approaches you in anger or in enmity.
(9) Hope always and everywhere in the yazads and make friends with such men as will profit you.
(10) Strive for the things of the yazads and of the Amahraspands and lay down your life for them (if need be).
(11) Tell no secret to a woman.
(12) Listen to all that you hear and do not repeat it at random.
(13) Do not let your wife and children (out of your sight) except for reasons of good manners (frahang) lest care and grievous annoyance come upon you and you rue it.
(14) Do not give (alms) out of season.
(15) Give a quick (? si' pas 'ut pêsh) answer (only) if it accords with moderation.
(16) Do not mock at anyone.
(17) Do not share your secrets with a wrong-headed man. (18) Do not make a choleric [bad tempered] man your travelling companion. (19) Do not take a frivolous man for your counsellor. (20) Do not make a rich man the companion of your table. (21) Do not make a drunkard your boon-companion. (22) Do not borrow from a man of bad character or base lineage or lend to him, for you will pay heavily in interest, and he will be forever at your door or will always be sending messengers to your house, and great loss will you suffer thereby. (23) Do not summon an ill-disposed person to help you. (24) Do not show your property to an envious man. (25) Do not put into force(?) a false judgement in the presence of rulers. (26) Do not listen to the words of calumniators and liars. (27) Do not be over-zealous in punishing others. (28) Do not pick a quarrel at a feast. (29) Do not strike others. (30) Do not strive for position.
(31) Consult men who are of gentle stock, experienced in affairs, clever, and of good character; make these your friends. (32) Take great care that no heavy burden is laid on you in battle.1 (33) Keep away from vengeful men in a position of power.
1. Translation uncertain.
(34) Do not come into conflict with a scribe. (35) Do not tell your secrets to a babbler.
(36) Hold a wise man whose position is exalted in high esteem, ask his opinion and listen to it.
(37) Do not tell a lie to anyone. (38) Do not accept the goods of any man who is devoid of shame. (39) Do not consciously wager on anything at all. (40) Do not take an oath on either what is true or what is false.
(41) When you are about to set up house, first take stock of the expense. (42) Woo the woman who is to be your wife yourself. (43) If you (already) have property, start by buying more irrigated agricultural land, for even if it fails to yield interest, the capital will remain.
(44) So far as you possibly can, do not bore your fellow men. (45) Do not seek to be avenged on others and do not try to cause them loss. (46) Be as generous with your property as you can. (47) Do not deceive anyone lest you come to grief thereby. (48) Hold your superiors in high esteem, make much of them, and listen to what they say. (49) Borrow only from relations and friends. (50) Cherish the woman who is modest and give her in marriage to a clever and knowledgeable man; for clever and knowledgeable men are like the good earth which yields all manner of produce when once the seed has been planted in it.
(51) Be plain in your speech. (52) Never speak without reflection. (53) Lend money only under agreed conditions (pat adhvên). (54) Cherish a wise and modest woman and ask her in marriage. (55) Choose a son-in-law who is good-natured, honest, and experienced even though he be poor, for he will (surely) receive riches from the yazads. (56) Do not mock at your elders, for you are subject to them. (57) Do not send a proud and pitiless man to prison, but choose prison-warders from among big men and (set) an intelligent man (over them).
(58) If you have a son, send him to a grammar-school when he is still a boy, for the art of reading and writing is exceedingly well seen. (59) Speak sharply only after much reflection, for there are times when it is better to speak out and times when it is better to hold your peace; (on the whole) to hold one's peace is better than to speak. (60) Choose a man who tells the truth as your messenger. (61) Do not appoint a bought2 slave above trustworthy and faithful servants. Spend according to your means. (62) Be courteous in your speech. (63) Keep your conversation courteous. (64) Keep your thoughts righteous. (65) Do not praise yourself; only so will you perform righteous deeds. (66) When in the presence of kings and princes do not appear to be without mercy. (67) Ask the advice of good men of mature age. (68) Accept nothing from a thief nor give anything to him: drive him rather away. (69) As you fear Hell, punish others only after due reflection. (70) Do not put your trust or confidence in anyone or anything at all.
2. Reading 'khrîtak for zatak.
(71) Make good use of authority so that you may obtain a good position (thereby). (72) Be without sin so that you may be without fear. (73) Be grateful so that you may be worthy of good things. (74) Be single-minded so that you may be faithful. (75) Speak the truth so that you may be trusted. (76) Be humble so that you may have many friends. (77) Have many friends so that you may enjoy a good repute. (78) Be of good repute so that you may live at ease. (79) Choose the better part and love your Religion so that you be saved (ahrov). (80) Think on the state of your soul so that you may go to Heaven. (81) Be generous so that you may go to Paradise (garothman).
(82) Do not seduce other men's wives, for that is a grievous sin for thy soul. (83) Do not maintain mean and ungrateful men, for they will not thank you. (84) Do not destroy your own soul for the sake of anger or vengeance. (85) When you feel an urgent desire to do or say (something), <ask> politely and say a prayer, for no one ever broke his back by saying his prayers or got foul breath by asking politely. (86) Do not address a low-born person first. (87) When you attend a gathering, do not sit next to a wrong-headed man so that you may not yourself appear wrong-headed. (88) Wherever you sit at a banquet, do not sit in the highest seat lest you be moved away therefrom and made to sit in a lower seat. (89) Do not rely on property and the goods of this world, for property and the goods of this world are like a bird that flies from one tree to another and stays on none. (90) Honour your father and mother, listen to them and obey them, for so long as a man's father and mother live, he is like a lion in the jungle which has no fear of anyone at all; but he who has neither father nor mother is like a widowed woman who is despoiled by men and can do nothing about it and whom all men despise. (91) Give your daughter to a clever and knowledgeable man, for a clever and knowledgeable man is like the good earth which yields up much grain once the seed is sown in it.
(92) If you would not be abused by others, do not abuse anyone. (93) Do not be violent or ill-considered in your speech, for the man who is violent or ill-considered in his speech is like a fire that falls upon a forest and burns up all birds and fish and creeping things. (94) Do not collaborate with a man who ill-treats his father and mother and with whom they are displeased, lest your justice be turned to injustice(?) and you be deprived of friends and have no pleasant intercourse with anyone. (95) Do not out of false modesty or shame deliver your soul up to Hell. (96) Do not say anything that has a double meaning. (97) When you sit in an assembly, do not sit next to a liar lest you yourself should suffer greatly thereby. (98) Take things easy (lit. 'be easy-footed') so that you may be a welcome guest. (99) Rise before dawn so that your work may prosper. (100) Do not make a new friend out of an old enemy, for an old enemy is like a black snake which does not forget old injuries for a hundred years. (101) Renew your friendship with old friends, for an old friend is like old wine which becomes better and more fit for the consumption of princes the older it is. (102) Praise the yazads and be glad of heart, for it is from the yazads that you will obtain an increase in the good things (of this world). (103) Do not curse a man of princely rank, for there are security officers in (all) the realm who decree what is good for (the king's) subjects.
(104) I say unto you, my son, that3 in the affairs of men the greatest(?) helper and the best is wisdom, for if one's wealth is scattered and lost or if one's livestock die, wisdom remains. (105) Strive to be firmly anchored in your Religion, for contentment is the highest wisdom (dânâkîh) and the greatest spiritual hope. (106) Keep your soul ever in mind. (107) Do not forsake your duty to preserve your good name. (108) Keep your hands from stealing, your feet from treading the path of undutifulness, and your mind from unlawful desires (varan), for whoso practices virtue obtains his reward, and whoso commits sin receives his punishment. (109) Whoso digs a pit for his enemies will fall into it himself.
3. Reading 'ku for 'kê.
(110) The good man lives at ease but the bad man suffers distress and grievous woe. (111) Marry a young wife. (112) Drink wine in moderation, for whoso drinks wine immoderately falls into many a sin. (113) Since you know well that a snake has many wiles, do not be over-hasty to touch one lest it bite you and you instantly die. (114) Even though you know well a stretch of water much frequented by bathers, do not be over-hasty in going into rough water lest the water carry you away and you instantly die. (115) Do not on any account be false to a contract lest you be held accountable(??) for it. (116) Do not rob others of their property nor keep (what has been robbed) nor add it to your own, for (then) your own (property) will be destroyed and vanish away, for when you carry off property that is not your own and keep it and <add> it to your own ... (gap in text) ...
(117) ... do not rejoice, for men are like a water-skin
full of air. When it is deflated, nothing remains. Men
are like suckling babes, creatures of habit who cling to
[Activities for each day of the month]
(Duties to be performed on different days of the month)
(119) On the day of Ohrmazd drink wine and make merry.
(120) On the day of Vohuman put on new clothes.
(121) On the day of Ardwahisht go to the Fire Temple.
(122) On the day of Shahrewar rejoice.
(123) On the day of Spandarmad till your land.
(124) On the day of Hordad dig your irrigation channels.
(125) On the day of Amurdad plant shrubs and trees.
(126) On the day of Day-pa-Adar wash your head and trim your hair and nails.
(127) On the day of Adar (Fire) go for a walk and do not bake bread for it is a grievous sin.
(128) On the day of Aban (the Waters) abstain from water and do not vex the waters.
(129) On the day of Khwarshed (the Sun) take your children to the grammar-school so that they may become literate and wise.
(130) On the day of Mah (the Moon) drink wine and hold converse with your friends and ask a boon of King Moon.
(131) On the day of Tir (Sirius) send your children to learn archery and jousting and horsemanship.
(132) On the day of Gosh (the Bull) see to the stables and train your oxen to the plough.
(133) On the day of Day-pa-Mihr wash your head and trim your hair and nails, and (pick) your grapes from the vine and throw them into the wine-press so that they may become good.
(134) On the day of Mihr, if you have been wronged by anyone, stand before Mihr (Mithra) and ask justice of him and cry out aloud (to him).
(135) On the day of Srosh ask a boon of the blessed Srosh for the salvation of your soul.
(136) On the day of Rashnu life is gay: do, in holiness, anything you will.
(137) On the day of Frawardin take no oath, and on that day sacrifice to the Farohars (departed spirits) of the blessed so that they may be the better pleased.
(138) On the day of Warharan lay the foundations of your house so that it may be speedily completed, and go out to battle and warfare so that you may return the victor.
(139) On the day of Ram summon your wife and do (with her) what is done and enjoy yourself take any suit (you may have) before the judges so that you may return victorious or acquitted.
(140) On the day of Wad (the Wind) confine yourself to words(?) and do not undertake anything new.
(141) On the day of Day-pa-Den do anything you like, bring your wife into your quarters, trim your hair and nails and clothe yourself.
(142) On the day of Den (the Religion) kill noxious beasts and reptiles.
(143) On the day of Ard buy any new thing (you need) and bring it home.
(144) On the day of Ashtad deliver over your mares, cows, and pack-animals to their males so that they may return in good health.
(145) On the day of Asman (the Sky) set out on a long journey so that you may return safely.
(146) On the day of Zam (the Earth) do not take medicine.
(147) On the day of Mahraspand mend your clothes, stitch them, and put them on, and take your wife to bed so that a keen-witted and goodly child may be born (to you).
(148) On the day of Anagran (the Endless Light) trim your
hair and nails and take your wife to bed so that an
exceptional child may be born (to you).
(149) Do not be overjoyed in4 good times nor over-distressed in bad times, for the good fortune of Time turns <to> misfortune and the misfortune of Time turns to good fortune, and there is no "up" that has not been preceded by a "down," and no "down" that is not followed by an "up," (150) Do not be gluttonous (varanîk) in eating your food, (151) and do not partake of all foods. Do not be over-hasty to attend the feasts and banquets of the great lest you return from them abashed. (152) For there are four things which are most harmful to the body of (mortal) men and make them have wrong ideas about their body. One is to glory in one's strength. One is the luxury of pride which (leads one) to pick a quarrel with a well-established (hangat) man. One is (the case of) the elderly man with a puerile character who weds an adolescent girl; and one is (the case of) the young man who weds an old woman. (153) It should be known that love of one's fellow men (proceeds) from a balanced mind (bavandak-mênishnîh), and good character from being nicely spoken. (154) And I say unto you, my son, that5 of all the things that give help to man wisdom is the best".
4. Reading 'kadh for 'chê.
5. Reading 'ku for 'kê.