מדרש אויף בראשית 29:27

Rabbi José said: From whom do we learn of the seven days of banquet? From our father Jacob. For when our father Jacob married Leah, he made a banquet with rejoicing for seven days, as it is said, "Fulfil the week of this one" (Gen. 29:27).

"Filled out the week." The seven days of Chuppah.

Jacob began to serve for a wife for seven years. He made a banquet and rejoicing for seven days, and married Rachel, as it is said, "Fulfil the week of this one" (Gen. 29:27). "And Jacob did so, and fulfilled the week of this one" (Gen. 29:28). All the men of the place were gathered together to show loving-kindness to our father Jacob, as it is said, "And Laban gathered together all the men of the place, and made a feast" (Gen. 29:22).