Chapter 19 describes the three holy men’s visit to Lot, followed by the promised destruction of Sodom. Only Lot and his two daughters end up making it out alive.
In chapters 20-21, we read more about Abraham’s travels and the promised birth of Isaac. Hagar and Ishmael are required to take leave and start their own life.
The thing to take away from these passages is the examples of the three women whose lives are detailed. The stories serve as lessons of the kind of person we want to strive to be.
Lot’s wife is what we don’t want to be. Her heart was completely attached to the things of the world. Though instructed not to look back upon falling Sodom (where she longed to be), she couldn’t help herself. For her disobedience, she became a pillar of salt (Genesis 19: 17, 26).
Then there’s Hagar. We can imagine she was a good woman, as the Lord had compassion for her and protected her once she had to make her own way. God even promised to make of Ishmael a great nation (Genesis 17:21-18).
However, Hagar and her son had a problem with pride. After Hagar conceived Ishmael, she threw Sarah’s up-to-then bareness in her face. We can imagine she taught her son this attitude, because he mocked and persecuted Sarah and Isaac (Genesis 21: 9, Galatians 4:28-30).
So Hagar wasn’t as set in the world as Lot’s wife, but her heart wasn’t pure. She didn’t live up to the high standards God sets for those with whom he makes special covenants.
There’s reason Sarah was chosen as the woman through whom the Lord’s covenant people–and ultimately the Savior himself–would come forth. She was pure in heart and dedicated to the Lord.
First, we can observe Sarah’s loyalty to Abraham in the way she looked to procure his well-being. In chapter 20 of Genesis, Sarah says she’s Abraham’s sister upon entering the territory of Abimelech (just as was the case in Egypt). This she does under instruction from Abraham, who doesn’t want Abimelech’s men to kill him over his wife.
Abimelech takes Sarah away to be part of his harem, but God protects her from being violated by bringing curses upon Abimelech’s house. The truth eventually gets out and everyone becomes friends. But Sarah didn’t say a word in her own prior to the Lord’s interference because her priority was her husband’s safety.
Later, we see Sarah’s faithfulness to the Lord in the way she handles the situation with Hagar and Ishmael. Some might interpret her actions as born out of jealousy. I don’t think that was the case. Remember, Sarah gave Hagar unto Abraham because she wanted him to have a son (which demonstrates her devotion to her husband).
When Sarah sees Ishmael mocking on the day Isaac is weaned, her words to Abraham are:
10 Wherefore she said unto Abraham, Cast out this bondwoman and her son: for the son of this bondwoman shall not be heir with my son, even with Isaac.
Sarah isn’t speaking of her own ideas when she says that Isaac, not Ishmael, is the legitimate heir. She’s merely reiterating what the Lord himself had stated (see Genesis 17: 19-21). She isn’t thinking about herself.
Rather, Sarah is looking forward in time to the fulfillment of God’s promises. She sees the wisdom in avoiding early on the conflicts that would arise between the two brothers, and in that vein calls for a separation (just as Abraham and Isaac agreed to separate when their men began fighting).
Sarah is the kind of person we should aspire to be and the kind of person we should aspire to marry. She lived the Gospel in word and deed. For her righteousness, she was blessed to be “a mother of nations” (Genesis 17: 16).