(18) Rabban Shimon ben Gamaliel used to say: on three things does the world stand: On justice, on truth and on peace, as it is said: “execute the judgment of truth and peace in your gates” (Zechariah 8:16).

Rav Ḥiyya bar Rav from Difti taught them a baraita with regard to the verse: “And it was the next day and Moses sat to judge the people and the people stood over Moses from the morning until the evening” (Exodus 18:13). Does it enter your mind that Moses would sit and judge all day long? If so, when was his Torah study accomplished? Rather, surely the verse is coming to tell you: Any judge who judges a true judgment truthfully, even if he sits in judgment only one hour, the verse ascribes to him as if he became a partner to the Holy One, Blessed be He, in the act of Creation, as by means of a true judgment he upholds the world (Me’iri).

(1) The commandment of belief in God: To believe that the world has one God that caused all that exists, and that all that is, and was, and will be forever and ever, is from His power and His will; and that He took us out out of Egypt and gave us the Torah - as it is stated (Exodus 20:2), "I am the Lord, your God, who took you out of the land of Egypt, etc." And its understanding is as if it said, "Know and believe that there is one God" - since the word, "I," indicates existence. And that which it stated, "who took you out, etc.," is to say that your hearts not seduce you to take the matter of your leaving the slavery of Egypt and the plagues of Egypt as the way of happenstance; but rather you should know that I am the One who took you out with will and providence - as He promised our forefathers, Avraham, Yitschak and Yaakov.

(2) The root of this commandment does not need elucidation. The matter is known and revealed to all that this belief is the foundation of the religion, and that one who does not believe in it denies a fundamental principle and has no share and merit with Israel. And the content of the belief is that he fix in his soul that such is the truth and that a change of (about a change of) this in any way be impossible. And if he be asked about it, he will respond to any enquirer that his heart believes this and he will not assent to a change in it, even if they say they will kill him [as a result]. As all of this - when he takes the thing from the potential to actuality, by which I mean to say when he puts into the words of his mouth what his heart decides - strengthens and fixes the belief of the heart. And if one merits to rise in the levels of wisdom, 'his heart will understand and his eyes will see' with a sealed proof that this belief that he believed is true and clear - it is impossible that there be something besides this - then he will fulfill this positive commandment [in the best way].

(3) The laws of this commandment - for example, that which it obligates us to believe about Him that all power and all greatness and strength and glory and all majesty and all blessing and all existence are in Him, and that we do not have the power or the intellect to grasp and to speak out His greatness and goodness, since His great virtue and majesty is only grasped by Himself; to deny about Him with all of our strength any lacking and anything that is the opposite of all perfections and all virtues, and the matters that come out from this, for example, to know that He is a perfect Being, without a body and not a power of a body, since lackings effect bodies, whereas He, may He be blessed, is not effected by any type of lacking, as we have said; and all the many things about this matter - are all elucidated in the books of those that know the wisdom of theology. Happy are those that merit it, as they can then fulfill this commandment with clarity (Mishneh Torah, Laws of Foundations of the Torah 1).

(4) And [it] is practiced in every place and at all times by males and females. And one who transgresses it has no portion and merit with Israel, as we have said. And this is from the commandments that does not have a specific time, since a man must live with this thought all the days of his life.