And Joseph knew his brethren, but they knew not him.
Joseph saw his brethren ... they knew not him. This is not wonderful. They were full-grown men-he was but a lad at parting. They were in their usual garb-he was in his official robes. They never dreamt of him as governor of Egypt, while he had been expecting them. They had but one face-he had ten persons to judge by.
Made himself strange ... spake roughly. It would be an injustice to Joseph's character to suppose that this stern manner was prompted by any vindictive feelings: he never indulged any resentment against others who had injured him. But he spoke in the authoritative tone of the governor, in order to elicit some much-longed-for intelligence respecting the state of his father's family, as well as to bring his brethren, by their own humiliation and distress, to a sense of the evils they had done to him.