Albert Barnes Commentary Ezra 4:8

"Rehum the chancellor and Shimshai the scribe wrote a letter against Jerusalem to Artaxerxes the king in this sort:" — Ezra 4:8 (ASV)

The chancellor - literally, “Lord of judgment;” the title, apparently, of the Persian governor of the Samaritan province. Every Persian governor was accompanied to his province by a “royal scribe” or “secretary,” who had a separate and independent authority.