What does Hebrews 7:9 mean?

The Bible often hints at a concept known as "federal headship." In this scheme, children are considered a "part" of their ancestors, especially their fathers. This is often used in discussions of sin and the fall of man; Adam sinned, and as the father of all men, he was the "federal head" of our race. Therefore, in a symbolic sense, we all sinned, since we were all part of Adam at the time he fell. In a similar sense, the author of Hebrews suggests that the priests of Levi, who came long after Abraham, were "still in the loins" of Abraham when he paid a tithe to Melchizedek (Hebrews 7:10).

Verses 9 and 10 give this statement while also making it clear that the point is entirely symbolic. This verse, in particular, explicitly uses the Greek phrase hōs epos eipein, literally meaning "so to speak." The tithe, which is given from the lesser to the greater, is used as further proof that the priesthood of Melchizedek, discussed in the prior verses, is greater than that of Aaron. It also demonstrates that Melchizedek is a greater figure than Abraham, since Abraham paid him a tithe. That tithe, according to this logic, is even more important than the one collected by the priests from their fellow Israelites.