Musar על שמואל ב 20:3

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.