John Gill Commentary Genesis 29:18

"And Jacob loved Rachel. And he said, I will serve thee seven years for Rachel thy younger daughter." — Genesis 29:18 (ASV)

And Jacob loved Rachel
As he seems to have done from the moment he saw her at the well, being beautiful, modest, humble, affable, diligent, and industrious:

and he said, I will serve you seven years for Rachel your younger
daughter :
signifying, that he desired no other wages for his service than that, that he might have her for his wife, at the end of seven years' servitude, which he was very willing to oblige himself to, on that condition; for having no money to give as a dowry, as was customary in those times, he proposed servitude instead of it; though Schmidt thinks this was contrary to custom, and that Laban treated his daughters like bondmaids, and such as are taken captives or strangers, and sold them, of which they complain, (Genesis 31:15) .