He used to say: A father merits a son with beauty, with [physical] strength, with [material] wealth, with wisdom [in Torah], and with years. And [re-garding] the number of generations [that is] before Him; for that is the time set [by him]. As it is stated: He proclaimed the generations from the beginning. [For] although it is stated with regard to the redemption from Egypt: And they will serve them and they will oppress them four hundred years, it is also stated: And the fourth generation shall return here.