Summary: Abraham and Sarah try to help God keep His promise.
Genesis is a book about God’s eternal plan to redeem His children from their slavery to sin and death. Adam fell, but God promised a Son who would defeat the serpent who had tricked him. Every chapter of the Bible is an account of how His promise is fulfilled, and Genesis 16 is no different.
Abraham was an idol worshipping Gentile, but God called him to a Promised Land where he would be blessed. He obeyed but had no son and feared his servant would inherit the promise. So, God appeared again and promised not only a son but innumerable descendants who would possess the land. Abraham believed God, and to establish the covenant formally, God walked the blood path to make the promise a certain guarantee.
But a lot of time passes, and Abraham (who is 85 years old at this point) and his wife, Sarah, aren’t getting any younger. They slip into a sort of panic as the batteries on their biological clocks are quickly going dead. It’s in this panic that Sarah forms a plan to help God accomplish His purposes; but her plan backfires and a son is born who is not according to the promise. In Galatians Paul tells us the meaning of this story, so I want to start there: Tell me, ye that desire to be under the law, do ye not hear the law? 22For it is written, that Abraham had two sons, the one by a bondmaid, the other by a freewoman. 23But he who was of the bondwoman was born after the flesh; but he of the freewoman was by promise. 24Which things are an allegory: for these are the two covenants; the one from the mount Sinai, which gendereth to bondage, which is Agar. 25For this Agar is mount Sinai in Arabia, and answereth to Jerusalem which now is, and is in bondage with her children. 26But Jerusalem which is above is free, which is the mother of us all. 27For it is written, Rejoice, thou barren that bearest not; break forth and cry, thou that travailest not: for the desolate hath many more children than she which hath an husband. 28Now we, brethren, as Isaac was, are the children of promise. 29But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now. 30Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman. 31So then, brethren, we are not children of the bondwoman, but of the free (Gal. 4:21-31).
Hagar and Ishmael are not heirs of the promise: “cast out the bondwoman and her son for the son of the bondwoman shall not be heir with the son of the free woman.” Later (Gen. 17:18-21) Abraham asks God to make His covenant with Ishmael instead of giving him another son, but God refuses saying, “I will establish my covenant with Isaac.” The whole point of this story we’re about to read (according to the Apostle Paul in the New Testament) is to make a distinction between the children of the promise and the children of the flesh. These two women and their descendants are allegories or symbols of God’s choice.
So, with this explanation in mind, let’s begin:
Now Sarai Abram’s wife bare him no children: and she had an handmaid, an Egyptian, whose name was Hagar. 2And 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.
Now you’ll remember that Abraham and Sarah had journeyed to Egypt during the famine in Canaan; they’d lied about their relationship as husband and wife so that the Egyptians wouldn’t kill Abraham to marry his widow, and Pharaoh (thinking they were brother and sister) brought Sarah into his house to marry her. It’s likely that Hagar was given to Abraham then as part of the dowry. Of course, when the truth was discovered, Abraham and Sarah were sent away with all their possessions which would have included Hagar.
So they’re waiting in the desert for some progress on the promise. And Sarah, being eager, decides that God must have meant for them to have a son through Hagar. The laws at that time and in that culture allowed for masters to produce children through their slaves, so it wasn’t an uncommon practice. And apparently Abraham agreed that Sarah was too old to have a child, and it seemed wise to him (looking at the circumstances with the logic of human wisdom), so he goes along with it:
And Abram hearkened to the voice of Sarai.
And this is his downfall, isn’t it? Just as Eve listened to the serpent when he questioned God’s word, Abraham listened to Sarah. He should rather have remembered the covenant God made with him at the blood path. After all, if God needs Sarah’s help in fulfilling His promise, then maybe she’s more deserving of worship than He. If God couldn’t keep His end of the bargain, then He made a mistake going through the blood path. But I don’t guess that crossed Abraham’s mind, so he agrees to the plan: