At the end of chapter 20, Abraham prays for Abimelech that his house be lifted from the curse that God put on them because of their sin against Sarah and Abraham ....because of Abraham ( and Sarah’s) sin... lying about her identity because the didn’t trust God..... and what was that curse??? Barren wombs!!! Interesting isn’t it! And it was almost immediately after this that Sarah finally became pregnant... with the son of promise!!! I think that’s amazing!