Genesis 16:2

And Sarai said unto Abram, Behold now, the LORD hath restrained me from bearing: I pray thee, go in unto my maid; it may be that I may obtain children by her. And Abram hearkened to the voice of Sarai.

The Lord hath restrained me from bearing. Eastern women in general have always displayed a passionate desire for a family: it is the result of their social condition in countries where the honour, influence, and strength of a household depend as much on the number of the sons as of the armed retainers belonging to it. The eagerness for offspring, however, displayed by Sarai (and other Hebrew women after her), while it partook in a certain degree of this common Oriental feeling, is traceable to a special cause: it arose from the hope of being the ancestress of the promised Messiah (the seed of God, Malachi 2:15). Having continued so long in that unblessed condition that she had no natural ground of hope that she would be a mother, she, after the lapse of ten years from the date of entrance into Canaan, bethought herself of an expedient for attaining the object of her fondly-cherished wishes by adopting the son of another woman; and accordingly she persuaded her husband to enter into her views, although the proposed connection had apparently formed no part of Abram's plan of life previous to his wife's suggestion.

It may be that I may obtain children by her, [Hebrew, 'uwlay (H194) 'ibaaneh (H1129) mimeenaah (H4480), perhaps I may be built up through her - i:e., obtain children by her] - (see the note at Genesis 30:3.)

And Abram hearkened to the voice of Sarai. The proposal, originating with Sarai, was entertained by both herself and Abram in the integrity of their hearts. Abram had on three different occasions been divinely assured of offspring: on the last, that his heir was to be a son of his own; and he was content to wait in believing confidence the accomplishment of the divine promise. But Sarai had never been mentioned in connection with this subject. Her hopes of giving birth to the promised seed had vanished with increasing age; and, concluding that she was not destined to enjoy that distinguished honour, she formed the purpose of reaching by proxy the happy consummation which was to all appearance denied to herself.