Anybody know anything more on Melchizedek? He is only mention…

Anybody know anything more on Melchizedek? He is only mention twice. Genesis and Hebrews. I’m paraphrasing but it says he was “High priest” and brought out bread and wine, blessed Abraham and Abraham tithed a 10th of everything he had.

I just find it interest this guy who is only mentioned twice could bless Abraham. And also I didn’t think a priesthood began back in that time?