This is either one of the most fascinating or frustrating chapters in Genesis.
It gives us the only highly detailed account of what was going on in the world at the time of Abram, with names of kings and cities and detailed accounts of battles and subjugations; but at the same time these details have yet to be found outside of Scripture.
It also gives us an account of Abram that expands our understanding of him. We know him as a man of faith willing to take risks, but also a timid man who cowers in front of other powerful men. He is generous, giving his nephew the choice of the land as well. Here, though, we see a man who takes on a powerful alliance of four kingdoms who have taken Lot hostage. And he wins.
If Abram has that capacity for battle, why hasn’t he taken the promised land for himself? He even refuses to take any personal winnings from the battle. He does not want to be indebted to the people in the land. He wants his blessing to be clearly from the Lord. That is likely the point of the story here as well. Abram is in the promised land because God has told him to be there. God has also said He would give the land to Abram’s descendants. Abram knows where success comes from. He is not about to take matter into his own hands. (Or is he? He shouldn’t be, but we are not talking about a perfect man of faith here, stay tuned!)
Finally, we get the most annoyingly interesting character in Scripture: Melchizedek. The King of Salem (Jerusalem) is seen a few times in the story of redemption. But the hints mentioned are the sort that send us—yet again—into a dangerously speculative mood. We have already seen how Genesis prompts all sorts of questions that it has no intention of answering. As frustrating as that is, asking the wrong questions of the text will only lead to problems.
Suffice it to say that Melchizedek reminds us that God is far more active in creation and history that the Bible will ever say. That knowledge is reassuring.