37:2 generations of Jacob. This is the last time the formula, “these are the generations of...,” is used in Genesis. This verse probably represents the signature of Jacob at the conclusion of the section originally written by Jacob (beginning at Genesis 25:19b). The information in the rest of Genesis must have come originally from Joseph and the other sons of Jacob. Possibly Moses recognized this by affixing a similar formula at its conclusion, in Exodus 1:1.
37:2 feeding the flock. Literally, “was shepherd over the flock.” Though he was slightly younger than the four brothers with him, he was very capable and had been placed in charge by his father. In this capacity, he was expected by his father to make full reports, and these necessarily included a record of the poor work of his brothers. Evidently the six sons of Leah had been assigned other duties in another place. Benjamin, his younger brother, was still a child, at home with his father.