(15) By the life of Pharaoh.--It was common in ancient times to swear by the king's life (see 1Samuel 17:55; 2Samuel 14:19 ), and even by the life of Jehovah (2Samuel 15:21; 2Kings 2:2; 2Kings 2:4; 2Kings 2:6). It is only in the stricter morality of the Gospel that such oaths are forbidden (Matthew 5:33-37).

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.Hereby ye shall be proved,.... Whether spies, or not, namely, by producing their youngest brother, said to be at home with his father:

by the life of Pharaoh ye shall not go forth hence, except your youngest brother come hither: the phrase, "by the life of Pharaoh", seems to be the form of an oath, as it was common with many nations, especially with the Scythians, who used to swear by the royal throne (a), and the Romans, in later times, by the life, health, and genius of their emperor; and this custom of swearing by the life of their king, or by his head, continued with the Egyptians, as Aben Ezra says, unto his times; though some take this to be a wish or prayer for the life of Pharaoh, and render it, "may Pharaoh live" (b), or, at most, but a strong asseveration, that as dear as the life of Pharaoh was to him, so surely they should not stir from the place where they were, unless their youngest brother Benjamin was brought thither.

(a) Herodot. Melpomene, sive, l. 4. c. 68. (b) "vivat Parhoh", Montanus, Junius & Tremellius; so Ainsworth and Lightfoot.