The repetition intensifies Abram's plea — he is not simply mentioning the issue, he is pressing it. This is earnest, persistent prayer. The phrase 'one born in my house' refers to a slave born in his household — the legal heir in the absence of a biological son. Abram wants God to take this seriously.
Memory phrase: Keep bringing your honest prayers to God.
Talk about it: Abram said the same worry twice. Is it okay to keep bringing the same request to God? Why?
Prayer: God, I am not giving up. Here is my honest heart again — I trust that You hear me and that You care.