Charles Ellicott Commentary Genesis 50:16-17

"And they sent a message unto Joseph, saying, Thy father did command before he died, saying, So shall ye say unto Joseph, Forgive, I pray thee now, the transgression of thy brethren, and their sin, for that they did unto thee evil. And now, we pray thee, forgive the transgression of the servants of the God of thy father. And Joseph wept when they spake unto him." — Genesis 50:16-17 (ASV)

Thy father did command ... — Many Jewish expositors consider that this was untrue, and that Jacob was never made aware of the fact that his brethren had sold Joseph into slavery. It is, however, probable, from Genesis 49:6, that Jacob not only knew of it, but saw in Simeon and Levi the chief offenders. But besides the father’s authority the message brings a twofold influence to bear upon Joseph: for first it reminds him that they were his brethren, and next, that they shared the same religious faith—no slight band of union in a country where the religion was so unlike their own.