Musar su Proverbi 17:7

The eighth section: One who praises himself about virtues that are not found in him. King Solomon, peace be upon him, said (Proverbs 17:7), “Lofty words are not fitting for a villain; much less lying words for a great man.” Its explanation is [that] a villain should not act proudly and raise himself up due to the virtues of his ancestors. For he said in the verse above this (Proverbs 17:6), “and the glory of children is their parents.” Much less should a great man honor himself with lies and say, “I did so, and spread and gave [gifts],” when he did not do so. And this is a disgrace for any person, but all the more so, a great man. And he disgraces the generosity that he has done; for he profaned his soul with what he did not do. For this will testify that all of the righteous deeds that he did were [only] for fame and praise. And our Rabbis, may their memory be blessed, said (Yerushalmi Shevi’t 10:3 at the end) that one who is honored according to the level of one who knows two tractates, but knows only one, must tell them - “I know only one.” All the more so is it forbidden to lie and boast, saying, “I have learned many like these.”