It was accepted by the culture for a matron's servant to be a surrogate mother. It was not, however, accepted by God. God does not contradict Himself. He will never sanction us to do that which is against His Word, even if it is accepted by society. Certainly, we cannot place all of the blame on Sarai, for if Abram had vetoed her plan, she could not have gone anywhere with it.
Temptation can come from the most unlikely places.
We must be careful. This stresses the importance for Christians to marry Christians, for if we can be tempted even by godly spouses, how much more we would be by ungodly ones. So after Abram had been living in Canaan ten years, Sarai his wife took her Egyptian maidservant Hagar and gave her to her husband to be his wife. He slept with Hagar, and she conceived. When she knew she was pregnant, she began to despise her mistress.