Sforno on Genesis 37:2/ספורנו על בראשית ל״ז:ב׳

1אלה תולדות יעקב, what happened to him, as a result of his “settling,” i.e. “retiring” there. (matters which he had not planned). Things described in Proverbs 27,1 as ילדי יום, brought on by the passage of time. Ever since Yaakov had left his father’s home what happened to him had the appearance of something not planned by him, not the result of his design. It is similar to the history of the Jewish people during the era of the first Temple. At any rate, the words וישב יעקב, Yaakov setlled down, remind us of the Jewish people in the land of Israel until the first expulsion. The words בארץ מגורי אביו, in the land where his father had been a stranger, remind us of the era of second Temple. This was followed by the destruction of Jewish statehood, and the loss of even the status of a satellite power, and our entering a long period of exile which will terminate only with the final redemption.

2היה רועה את אחיו בצאן, he was giving guidance to them and instructed them in the finer points of being successful shepherds.

3והוא נער, if, in spite of this, he badmouthed his brothers, this was due to his being still an adolescent, not as mature as he should have been or as his intellect made him appear to be. He was not experienced enough to realise what the ultimate effect of his badmouthing his brothers would turn out to be. While it is true that as a relative youngster at 30 he became the mentor of the wisest men in Egypt, the foremost political power, at the tender age of 17 he still had a lot to learn. (compare his wisdom as expressed in Psalms 105,22 where aged people are described as wise, whereas in Shabbat 89 we are taught that mature wisdom cannot be expected to be found amongst the physically young.

4ויבא יוסף את דבתם רעה, he told his father that his brothers, because of unintentional errors, i.e. lack of professional competence, caused him financial losses in his flocks, seeing that at the time they were preoccupied primarily with increasing their material wealth.