Musar su Deuteronomio 27:26

And now understand - listen to this, for it is a great principle. It is true that there are righteous people who sometimes stumble into sin - like the matter that is stated (Ecclesiastes 7:20), "For there is no man that is righteous on earth, who does good and does not sin." However they conquer their impulses from in front of them. And if they do fall to sin once, they will not repeat it. [Rather] they will have it taken away from in front of them and repent. However anyone who is not careful of a particular sin and does not take upon himself to guard against it - even if it is from the light ones [and] even though he guards himself against all of the [other] transgressions of the Torah - the Sages of Israel call a habitual sinner (mumar) about one thing (Chullin 4b); he is counted with the sinners, and his sin is too great to bear. For surely if a slave said to his master, "I will do everything you tell me except for one thing," he has already broken his master's yoke from upon himself and will do what is proper in his [own] eyes. And this whole matter is stated [in] (Deuteronomy 27:26), "Cursed be he who will not uphold the words of this Torah, to do them" - the explanation of the matter is that he does not accept upon himself to fulfill all of the words of the Torah, from beginning to end. And what indicates this [is the phrase], "who will not uphold [...] to do" - and it did not state, "who will not do them."

And behold the punishment for the nullification of a commandment is explained in the Torah, as it is stated (Deuteronomy 27:26), “Cursed is the one who does not fulfill the words of this Torah, to do them.” It states, “to do them” - teaching that this is stated about the nullification of a commanded act.

And know that a creature is obligated to be a faithful agent and understanding servant in all of the craftful work of his Master. And a faithful worker will be quick at this craft and supervise the craft of his fellow workers. His eyes will be upon their ways, to see if they are faithful; and he will warn them and inform about the work they should do. For his desire and want is that the work of his Master be done without deceit. Therefore, he strengthens those doing the work [to do it right]. And our Rabbis, may their memory be blessed, said in the Sifrei (Yerushalmi Sotah 4:4), “‘Cursed is the one who does not fulfill’ (Deuteronomy 27:26), - a man who has studied, reviewed, taught others and fulfilled the Torah and the commandments, but has not strengthened [others to do so] is included in ‘who does not fulfill.’”