According to Fabre d'Olivet, Lysis of Taras, a disciple of Pythagoras, is responsible for writing the verses that, is unanimously believed, represent the core beliefs of Pythagoras and his school. Their philosophy was secret, meaning that you needed to be initiated into one of the various clubs spread across Magna Graecia. Reading these verses should go hand in hand with reading the commentaries of Hierocles of Alexandria.
I present here the first part named "Practical Virtues", this part is centered around ethics. The first three verses are difficult to understand by most modern people because of the three levels, the Immortal Gods, the Heroes and the Terrestrial Daemons. For Christian and Muslims alike this sounds more like blasphemy, but don't be scared.
The Immortal Gods are closest to the Creator, for adherents to the Abrahamic religions you can understand them as being Angels, Archangels, Cherubim, Seraphim and so on (depending on the religions and theologists), that's why you need to honor them "as they are established and ordained by the Law", some are higher then others. But how do you honor them? The answer is by accepting the good that comes from them, not by sacrifices because they don't need sacrifices. There are also two Pythagorean sayings: "You will honor God perfectly if you behave yourself so that your soul may become his Image" and "Any man who thinks God needs gifts holds himself higher than God". Also "God has not upon Earth a place more fit for him to dwell in, than a pure Soul" is also worth mentioning.
The Heroes are the good spirits (they occupy the middle part and think and act only in accordance to the Law) while the Terrestrial Daemons are (contrary to the name Daemon having a bad connotation) the souls of men who are adorned with Truth and Virtue, full of Knowledge and Light. Some believe that Terrestrial Daemons evolve into Heroes. Most people sway between light and darkness, light understood as embracing the Law and God while darkness understood as a mind that does not comprehend the beauty of God.
The rest of the Verses in this first part are rather self-explained. If any of you has difficulties in understanding them, write a comment and I will expand on them. I also recommend reading Not Knowing God, in the Muslim esoteric world it is widely believed that Pythagoras was a student of Hermes.
1. First honor the Immortal Gods, as they are established and ordained by the Law.
2. Reverence the Oath, and next the Heroes, full of goodness and light.
3. Honor likewise the Terrestrial Daemons by rendering them the worship lawfully due to them.
4. Honor likewise your parents, and those most nearly related to you.
5. Of all the rest of mankind, make friends the ones distinguished by virtue.
6. Always listen to his mild exhortations, and take example from his virtuous and useful actions.
7. Avoid as much as possible hating your friend for a slight fault.
8. [And understand that] power is a near neighbour to necessity.
9. Know that all these things are as I have told you; and learn to vanquish the following:--
10. First gluttony, then laziness, luxury, and anger.
11. Do nothing for which you should be ashamed, neither in the presence of others, nor privately;
12. And above all things respect yourself.
13. In the next place, do justice with your actions and your words.
14. And in any circumstance don't behave yourself without thinking.
15. But always remember that man is destined to die.
16. And that wealth as it is acquired, so too it is lost.
17. Concerning all the calamities that men suffer by divine fortune,
18. Support them with patience, be it what it may, and never repine at it.
19. But endeavor what you can to remedy it.
20. And consider that fate guards good men from many of these misfortunes.
21. People say good and bad things
22. Don't show to these words too much appreciation, nor reject them.
23. Even if you hear lies, endure them with patience and kindness.
24. Observe well, on every occasion, what I am going to tell you:
25. Let no man either by his words, or by his deeds, ever seduce you.
26. Nor entice you to say or to do what is harmful for you.
27. Consult and deliberate before you act, that you may not commit foolish actions,
28. for only a miserable man speaks and acts thoughtlessly.
29. But do that which will not afflict you afterwards, nor oblige you to repent.
30. Never do anything which you do not understand;
31. But learn all you should know, and by that means you will lead a happy life.
32. Do not neglect the health of your body;
33. But drink, eat and exercise with measure,
34. and through measure I mean what will never hinder you.
35. Accustom yourself to a way of living that is simple and decent without luxury.
36. Avoid doing that which will bring envy.
37. Do not spend beyond measure, like those that do not know where good is found.
38. Neither be selfish; a due measure is good in all things.
39. Do only the things that cannot hurt you, and deliberate before you do them.
40. Don't let sleep to close you eyelids,
41. until you had examined with your reason all your actions of the day.
42. With what did I go wrong? What have I done? What have I omitted that I should have done?
43. If in this examination you find that you had done wrong, admonish yourself severely for it;
44. And if you had done good, rejoice.
45. Practice thoroughly all these things; meditate on them well; you ought to love them with all your heart,
46. And you will be on the path of divine virtue.
47. I swear it by him who has transmitted into our souls the Sacred Quaternion, the source of nature, whose cause is eternal.