God had called Abraham years before. Genesis 12:1-3
God affirms to Abraham what He will do for him.
GOD'S CALL - Vss. 1-3
He is Almighty God, and Abraham is to walk before Him perfectly. Vs. 1
God promises to keep His covenant with Abraham and to multiply him exceedingly. Vs. 2
GOD'S COVENANT - Vss. 4-14
God's covenant with Abraham would make Abraham and his descendants great. Vss.4-8
God's covenant was to signified by the act of circumcision. Vss. 9-14
GOD'S CHOICE - Vss. 15-22
It was Sarah who was going to have a child, through which all these promises would be kept. God's choice was a child named Isaac, who's name means "laughter".