'Expert' in the Bible

This is the text of the letter King Artaxerxes gave to Ezra the priest and scribe, an expert in matters of the Lord’s commands and statutes for Israel:

Artaxerxes, king of kings, to Ezra the priest, an expert in the law of the God of heaven: Greetings.

I, King Artaxerxes, issue a decree to all the treasurers in the region west of the Euphrates River: Whatever Ezra the priest, an expert in the law of the God of heaven, asks of you must be provided promptly,