GEN1093 … gratitude is a fundamental principle of our holy Torah as the author of the Chinuch notes in his commentary on [this verse]: “The roots of this commandment are that one ought to be grateful and benevolent towards one who did something good for him, and not be duplicitous, two-faced and ungrateful.   For this is an evil trait, and one that is utterly despicable in the eyes of God and men … And when he will imbed this trait in his soul, he will be elevated by it to recognize the goodness of God towards him.” EYES 68