Genesis 16:2

And Sarai said unto Abram, behold now, the Lord hath
restrained me from bearing
Or, "hath shut me up" ^F4; that is, her womb, as were the wombs of the house of Abimelech, ( Genesis 20:18 ) ; so that she could not conceive and bear children; she now at this age despaired of having children, perceiving very probably that it ceased to be with her after the manner of women; and this she refers to the will and power of God; for, as children are his gift, and an heritage from him, ( Psalms 127:3 ) , so it is his will and pleasure sometimes to withhold this blessing from those who are very desirous of them:

I pray thee go in unto my maid;
Hagar, the Egyptian before mentioned; her meaning is, that he would take her to wife, and use her as such:

it may be that I may obtain children by her;
for whatsoever were born of her handmaid, and in her house, were her own, and so she should account them, and especially as they would be her husband's, see ( Exodus 21:4 ) ; or, "may be builded by her" ^F5; for women, by bearing children, build up an house, see ( Ruth 4:11 ) ; hence a son in Hebrew is called "ben", from "banah", to build:

and Abram hearkened to the voice of Sarai;
without consulting God about it, the proposal being agreeable to the flesh, which may be imputed to the infirmity of the good man; though it does not appear to arise from previous lust predominant in him; but both Sarai's proposal, and his compliance with it, might be owing to the eager desire of each after the promised seed; they both believed the promise, but did not know it, being not as yet revealed, that Abram should have a son by Sarai; so that Sarai knowing her own case and circumstances, might conclude it was to be by another, and by her handmaid; and Abram might reason and judge after the same manner, which inclined him to listen to her: Josephus ^F6 says, indeed, that Sarai moved this to Abram by the direction and order of God himself; and the Jewish writers say ^F7, that Abram hearkened to the Holy Spirit of God that was in her.