It is interesting here. I do not know if you picked up on it but twice, Moses, the writer of this book, clarifies that Hagar, Sarah's maid, is the Egyptian, the sojourner. Now, this situation is actually a bit reversed from a situation that happened a few years back. She is a sojourner in a foreign land. But I want to call attention here to the first instance of this underlying Hebrew word translated Egyptian four chapters earlier. Turn back there with me.
Now we are going back to Genesis 16 and we see this time it is Abram taking Hagar, the Egyptian who is the sojourner in the land of Canaan. And I think it is basically God saying, "Abram, you knew better. You saw the same thing, you saw what happened when Pharaoh tried to do this to you, and here you are, you did it to Hagar! Don't you see how I punished him?" Now, it is clear that Sarah was a bit desperate here and she wanted to take matters into her own hands, but Abram could have refused. And I think it is part of becoming at-one with our spouses by the way, right? It is not just blindly listening, it is having a conversation. "What does God really want from this situation? What should we do?" And it is that level of reciprocity and relationship that allows us to be better together and to get to a better answer.
Abram just listened. He did not have that conversation. I think in his gut he probably knew a little better but maybe not. We should note that it was after 10 years that this happens. So after 10 years that Abram is living in the land of Canaan he goes in to Hagar and we see the result. Immediately, as soon as he has multiple wives, turmoil and division. Sarai wants to send her handmaid away, only for God to bring her back. And we see this account of having more than one wife ends very poorly and causes issues for many generations to come.