Musar su II Samuele 20:48

And our Rabbis, may their memory be blessed, stated (Avot 5:19), "Whoever possesses these three things, he is of the disciples of Abraham, our father [...] A good eye, a humble spirit and a moderate appetite." And the meaning of a humble spirit is that he does not follow his physical desire even with permissible things. [This is] like we find that Abraham stated (Genesis 12:11) "Behold I know what a beautiful woman you are" - as he had not stared at her until that day, to contemplate the character of her beauty. And our Rabbis, may their memory be blessed, stated (Yerushalmi Sanhedrin 2:3) about that which is written (II Samuel 20:3), "and they remained in seclusion until the day they died, in living widowhood" - that each day David would command that their heads be beautified and that perfumes be given to them to adorn them in order to provoke his desire and to [then] subdue it, when he would conquer his impulse for them, in order to atone for himself about the matter of Bathsheba.

Do not believe the counsel of one who hates and is inimical, as it is said: "But the kisses of an enemy are importunate" (Prov. 27:6). And know that many people express love with their words but it is possible that they are total enemies in their heart, and it is necessary that you recognize them and do not put your faith in them as it is said: "He that hates dissembles with his lips while he lays up treachery within him" (Ibid. 26:24). And even though he speaks to you with a smooth tongue and speaks tender words, do not incline your heart to him as it is said: "When he speaks graciously, do not believe him for there are seven abominations in his heart" (Prov. 26:25). And this is the type of conduct that Joab showed to Abner, son of Ner (II Sam. 3:27) and to Amasa, son of Yeter (II Sam. 20:9-10) (peace and love) until he killed them, and as Ishmael son of Nethaniah did with Gedaliah, son of Ahikam until he slew him (Jer. 41:1-2). One of the Sages said: "The best plan of those you can plot against your enemy is to turn him to your love (to make a friend of him) if you can."