ציטירנדיקער פּירוש אויף תהילים 38:20

כי את שבע כבשות תקח מידי, ”for the seven sheep accept from me;” because Avraham made this gift to Avimelech, G-d said to him: “because you have given him seven sheep, I will let your descendants wait seven generations during which his descendants will ruin seven locations in which the Jewish people will have their abode. They are: the Tabernacle in Gilgal, Shiloh, Nov, Giveon, and two permanent Temples. Furthermore the Holy Ark was exiled in the territory of the Philistine for a period of seven months during the period beginning with the death of the High Priest Eli. (Samuel I 6,1.) All of this is referred to in the Book of Psalms 38,20: ואויבי חיים עצמו; David meant to say: the three generations that Avraham gave away to Avimelech had to be paid for by his descendants with seven generations. There were seven generations between Avraham and Moses, and Pharaoh, a descendant of Avimelech was still alive. [The seven generations comprise Avraham, Yitzchok, Yaakov, Levi, Kehat, Amram, Moses.]