Ge 35:22 ...Now the sons of Jacob were twelve:

23 the sons of Leah were Reuben, Jacob's firstborn, and Simeon, Levi, Judah, Issachar, and Zebulun;

24 the sons of Rachel were Joseph and Benjamin;

25 the sons of Bilhah, Rachel's maidservant, were Dan and Naphtali;

26 and the sons of Zilpah, Leah's maidservant, were Gad and Asher. These were the sons of Jacob who were born to him in Padan Aram.

Moses here found it necessary to rehearse again the list of Jacob's sons because of the birth of Benjamin. Moreover, he is also showing that the promise of God of descendants to Jacob is in the works and being progressively fulfilled. At this point, they were twelve, but later on become the nation Israel itself.

The emphasis here is the fact that they were of Jacob. It is stated at the end of verse 22 and restated again, for emphasis, at the end of  verse 26. Since they were of Jacob, they must follow his steps in returning back to the land promised to him with all the other attendant promises to be fulfilled there.