Genesis 16:3

And Sarai, Abram's wife, took Hagar her maid, the Egyptian,
&c.] Took her by the hand, it is probable, and led her into the apartment where Abram was, and presented her to him; their characters are very exactly described, and the contrast beautifully given, that the affair might be the more remarkable and observable:

after Abram had dwelt ten years in the land of Canaan;
so that he was now eighty five years of age, for he was sventy five when he departed from Haran and came into Canaan, ( Genesis 12:4 ) ; and Sarai, being ten years younger than he, must be sventy five; the Jews from hence have formed a rule or canon; that if a man marries a woman, and she has no children in ten years, he is obliged to marry another ^F8:

and gave her to her husband Abram to be his wife;
his secondary wife, or concubine; which, though contrary to the first institution of marriage, was connived at of God, and was practised by good men: nothing can excuse them but their earnest desire after the Messiah, the promised seed; and one may conclude, that nothing but this especially could move Sarai to take such a step, so contrary to the temper and disposition of women in common.