1 ¶ And when Abram was ninety years old and nine, the LORD appeared to Abram, and said unto him, I am the Almighty God; walk before me, and be thou perfect. 2 And I will make my covenant between me and thee, and will multiply thee exceedingly. 3 And Abram fell on his face: and God talked with him, saying,
4 ¶ As for me, behold, my covenant is with thee, and thou shalt be a father of many nations. 5 Neither shall thy name any more be called Abram, but thy name shall be Abraham; for a father of many nations have I made thee. 6 And I will make thee exceeding fruitful, and I will make nations of thee, and kings shall come out of thee.
Thirteen years after Ishmael is born God appeared to Abram. To be perfect is be finished or completed.
2Chronicles 8:16 Now all the work of Solomon was prepared unto the day of the foundation of the house of the LORD, and until it was finished. So the house of the LORD was perfected.
It is to be complete in all the will of God.
Col 4:12 Epaphras, who is one of you, a servant of Christ, saluteth you, always labouring fervently for you in prayers, that ye may stand perfect and complete in all the will of God.
A perfect man is an upright man, fearing God and avoiding evil.
Job 1:1 There was a man in the land of Uz, whose name was Job; and that man was perfect and upright, and one that feared God, and eschewed evil.
He seeks to be like God, to hold close the principles of God as expressed in the popularly called Sermon on the Mount.
Matthew 5:48 Be ye therefore perfect, even as your Father which is in heaven is perfect.
God reaffirms His covenant with Himself regarding Abram. He will make Abram the father of many nations. Nations in the Bible are not like the modern nation-state. The implication is more of an ethnic group, a tribe, or a people. Abraham will be the physical progenitor of the Arabs, the Jews, Midianites, and others. But, we will see eventually that he gives everything he has to Isaac, the child of promise.
Abram’s name is changed to Abraham which means, read the text, father of many nations. Kings will come from him.