Rich, I have used these very verses to demonstrate that the Christians to whom the author of Hebrews is writing ought to have already understood that Melchizedek foreshadowed Christ (see 5:1-11). There are those who might say that we shouldn't make typological connections unless the NT explicitly makes them for us, but had these Hebrew Christians already understood the connection, the author might never had made it explicit for us! In other words, additional typological connections in the OT to Christ are legitimate even if they aren't explicitly made in the NT.
