Musar su Genesi 27:12

And the third section: One that comes with deception and deceptive words to prevent good from someone and to bring the good to himself. It is not to rob his fellow of something that is his nor to extort him. Rather he puts his eye upon a good that will be coming to his fellow in the future, and ambushes it to bring it to himself by the falsehood of his words; or his lying words cause his fellow to give it to him as a gift. And the main punishment is for the lie. Indeed, the punishment of the lie is enlarged if it causes a loss to someone besides himself, even though the main part of the punishment is not for the loss [here] - for he did not cause him to lose something that he had acquired. It is like the matter that our Rabbis, may their memory be blessed, said (Sanhedrin 92a), “Anyone who alters [the truth in] his speech, it is as though he worships idols. As, it is stated (Genesis 27:12), ‘Maybe my father will feel me, and I shall seem to him a deceiver (metate’a)’; and it is written there (Jeremiah 10:15) [regarding idolatry], ‘They are vanity, the work of deception [tatuim].’” And our Rabbis, may their memory be blessed, said that it was as if he worshipped idolatry [here] - they brought it to the extreme and other (and it appears to me that it needs to say, to the final extreme). For he is (traded) (it needs to say, hidden - and it is from the usage of the verse [Isaiah 28:15], “We have hidden in falsehood” - and so is it found in the Chapter on Falsehood in the Paths of the Righteous, the chapters of which are built upon the pearls of this holy book Y. B.) in falsehood and girded in vanity.

The third category is where one lies to his fellow not to rob him of anything he possesses, but he learns that a certain good thing is going to come to his fellow in the future, and so with falsehood and with cunning he praises this good fortune that is coming, and makes it appear that he has a share in it. Or he lies to his fellow until he gives him a gift, for example, he brings him good tidings — false tidings — in order to get a gift because of this. And there are many similar cases. And our Sages, of blessed memory, said, "Whoever dissembles in his speech is as though he had practiced idolatry" (Sanh. 92a). As it is said, "My father peradventure will feel me, and I shall seem to him as a mocker" (Gen. 27:12). And it is said, concerning idolatry, "They are vanity, a work of delusion" (Jer. 10:15). Now this does not mean that one who lies is actually like one who worships idols, but the resemblance is there, for he conceals himself in falsehood and is helped by empty things.