וְתַ֗חַת כִּ֤י אָהַב֙ אֶת־אֲבֹתֶ֔יךָ וַיִּבְחַ֥ר בְּזַרְע֖וֹ אַחֲרָ֑יו וַיּוֹצִֽאֲךָ֧ בְּפָנָ֛יו בְּכֹח֥וֹ הַגָּדֹ֖ל מִמִּצְרָֽיִם׃
And because He loved thy fathers, and chose their seed after them, and brought thee out with His presence, with His great power, out of Egypt,
Rashi on Deuteronomy
ותחת כי אהב AND BECAUSE HE LOVED — i.e., and all this was because He loved thy fathers.
Sforno on Deuteronomy
ותחת כי אהב את אבותיך, having done all this because He loved your patriarchs, ויבחר בזרעו, He chose the descendants of only one of them (Yaakov) .
Rashbam on Deuteronomy
ויוציאך בפניו, as documented in Exodus 12,12 and 23,21.