Genesis 29:18

אעבדך שבע שנים I WILL SERVE THEE SEVEN YEARS — These are the “few days” of which his mother had spoken to him (27:44)): “And thou shalt tarry with him a few days”. You can see that this is so, for it is written (v. 20) “And they (the seven years) were in his eyes (i.e. according to his view) the few days” of which his mother had spoken (Genesis Rabbah 70:17). ברחל בתך הקטנה (literally, for Rachel, thy daughter, the younger one) — What reason was there for mentioning all these detailed descriptions of Rachel? Because he (Jacob) knew that he (Laban) was a deceiver. He said to him, “I will serve thee for Rachel”: and should you say that I mean any other Rachel out of the street, therefore I say “your daughter”. Should you say, “I will change Leah’s name and call her Rachel”, I say “your younger one”. In spite of this, however, all these precautions did not avail, for he did actually deceive him (Genesis Rabbah 70:17).

וַיֶּאֱהַ֥ב יַעֲקֹ֖ב אֶת־רָחֵ֑ל וַיֹּ֗אמֶר אֶֽעֱבׇדְךָ֙ שֶׁ֣בַע שָׁנִ֔ים בְּרָחֵ֥ל בִּתְּךָ֖ הַקְּטַנָּֽה׃

And Ya῾aqov loved Raĥel; and said, I will serve thee seven years for Raĥel thy younger daughter.