What does Genesis 16:2 mean?

Abram possessed a direct promise from the Lord that he would have a flesh-and-blood heir, his own son (Genesis 15:4). As of this time, however, this has still not happened, and Abram is in his mid-80s (Genesis 16:16). Interestingly, Sarai holds the Lord responsible for her inability to bear children. In her mind, He is the one preventing this from happening. As a matter of fact, God may have been doing exactly that: executing His plan for their lives in His own timing. Sarai, though, didn't want to wait any longer to see what would happen.

Her plan may well have been a normal custom in the culture of their day. If a wife could not bear a child herself, she could assign the role to a servant who would become another wife to the husband. If the servant became pregnant, the child would still belong to the first wife, as the servant was her property. As repulsive as that may sound to our modern ears, it was the way of the time. And, the "slavery" of that era was very different from the brutality modern readers assume when they encounter that word.

Still, this must not have been something Abram had ever chosen to do before. He had countless servants. He surely could have had any number of wives. And yet, to this point, Abram had remained committed to seeing God's promise fulfilled through Sarai and no other woman. Now, however, he allows Sarai to convince him to try it. It will become clear that this is not the way God intends to build His covenant people.