16 But in the fourth generation they shall return hither: for as yet the iniquities of the Amorrhites are not at the full until this present time. 17 And when the sun was set, there arose a dark mist, and there appeared a smoking furnace and a lamp of fire passing between those divisions. 18 That day God made a covenant with Abram, saying: To thy seed will I give this land, from the river of Egypt even to the great river Euphrates. 19 The Cineans and Cenezites, the Cedmonites, 20 And the Hethites, and the Pherezites, the Raphaim also,
21 And the Amorrhites, and the Chanaanites, and the Gergesites, and the Jebusites
1 Now Sarai the wife of Abram, had brought forth no children; but having a handmaid, an Egyptian, named Agar, 2 She said to her husband: Behold, the Lord hath restrained me from bearing: go in unto my handmaid, it may be I may have children of her at least. And when he agreed to her request, 3 She took Agar the Egyptian her handmaid, ten years after they first dwelt in the land of Chanaan, and gave her to her husband to wife. 4 And he went in to her. But she, perceiving that she was with child, despised her mistress.
Genesis 15:16-21, 16:1-4
Now we know where the idea came from to use surrogate mothers. Not always a good idea, since it causes jealousy in the one who cannot produce from their own body. And also from the one who bears the fruit. Not always an easy situation. It tends to play out in our time as well, woman barren and seeking to produce a child of their own. We have come a very long way since then. Science has managed new ways for mothers to bear their own children, but without love or being part of a family. Where man and wife become one in unity and bear fruit from the seed of life. Now it's become a labor of selfishness to produce a child without love from two people united in faith, hope and love. Where a single person seeks to create a life alone. Jealousy now has been removed, so has the love between a man and a woman and the purpose that God had made them for.