(8) Joseph knew.--As this is twice repeated, some suppose that Joseph (in Genesis 42:7) had only a suspicion, from their dress and appearance, that these Canaanites were his brethren; but that when they spake the Hebrew tongue (comp. Genesis 42:23), every doubt was removed. They would not recognize him, as he used the Egyptian language, was clad in a white linen dress, and being but seventeen when sold, had during the twenty years of separation changed in appearance much more than they had.

Verse 8. - And Joseph knew his brethren, but they knew not him. The lapse of time since the tragedy of Dothan, twenty years before, the high position occupied by Joseph, the Egyptian manners he had by this time assumed, and the strange tongue m which he conversed with them, all conspired to prevent Jacob's sons from recognizing their younger brother; while the facts that Joseph's brethren were all grown men when he had last looked upon them, that he was quite familiar with their appearances, and that he perfectly understood their speech, would account for his almost instantaneous detection of them.

42:7-20 Joseph was hard upon his brethren, not from a spirit of revenge, but to bring them to repentance. Not seeing his brother Benjamin, he suspected that they had made away with him, and he gave them occasion to speak of their father and brother. God, in his providence, sometimes seems harsh with those he loves, and speaks roughly to those for whom yet he has great mercy in store. Joseph settled at last, that one of them should be left, and the rest go home and fetch Benjamin. It was a very encouraging word he said to them, I fear God; as if he had said, You may be assured I will do you no wrong; I dare not, for I know there is one higher than I. With those that fear God, we may expect fair dealing.And Joseph knew his brethren, but they knew not him. It being about twenty two years since they saw him, and then he was young, and his beard not grown, as now it was; and besides, he was clothed as a prince, and spoke the Egyptian language; and being in such great grandeur and splendour, and in such power and authority, and having such a retinue attending him, they never once thought of him, whom they supposed might be dead, having never heard of him all this time; or, however, it could not come into their minds, that he whom they sold for a slave could ever be governor of the land of Egypt.