Years have passed. Abram is ninety-nine when the LORD appears to him again. God makes Himself known as the Almighty and says, “Walk before me, and be thou perfect” (Genesis 17:1). The week began with a command to go to a land God would show him. Now it concerns not only the road to a place, but a life lived before God's face.
God repeats His covenant and speaks again of what He will do. Abram is to be the father of many nations. His name becomes Abraham; Sarai will be called Sarah. That change of name is all the more striking alongside Babel, where people wanted to make a name for themselves (Genesis 11:4). Abraham receives his new name from God. Yet the new name does not mean he already holds the fulfilment in his hands.
God also speaks of a son Sarah will bear: Isaac. And when Abraham asks about Ishmael, that son is not forgotten. God promises to bless him and make him a great nation, while expressly saying that the covenant announced here will be established with Isaac (Genesis 17:19–21). Scripture places both statements side by side.
The covenant also receives a visible sign in the flesh: circumcision. Genesis describes not only what Abraham receives but how he responds. On that very day he does what God has commanded him. Obedience is a real and important response. But it does not come before God's first speaking and promising.
Later Deuteronomy 30:6 speaks of a circumcision of the heart which the LORD Himself will bring about so that His people love Him. That is a further connection within Scripture, not a reason to erase the concrete covenant sign of Genesis 17. And when Revelation 2:17 speaks of a new name, we hear again that identity can be received. These are related images, not the same event.
So I read this final portion as a call not to remain at the beginning of the road. God's word calls Abram out, sustains him along the way, and finally calls him to walk before His face. Faith does not remain without a response. But our response may rest upon the faithfulness of the One who spoke first.