The Story of Melchizedek

After Abraham returned from defeating Kedor Lot O'Mear and the kings allied with him, the king of Sodom came out to meet him. But then Melchizedek, king of Salem, got there first. And he greeted Abraham, weary from war and so on, brings bread and wine to refresh him. He was a priest of God most high. Why is this guy significant for understanding Jesus' priesthood? Let's go back to Hebrews here.