This speaks about scripture as if it were a person who could witness about something. AT: "For God witnesses about him through the scriptures" or "For this is what was written about him in the scripture" (See: [[rc://en/ta/man/translate/figs-personification]])
There were two groups of priests. One was made up of the descendants of Levi. The other was made up of Melchizedek and Jesus Christ. AT: "according to the line of Melchizedek" or "according to the priesthood of Melchizedek"