Albert Barnes Commentary Ezra 2:63

"And the governor said unto them, that they should not eat of the most holy things, till there stood up a priest with Urim and with Thummim." — Ezra 2:63 (ASV)

The Tirshatha - that is, Zerubbabel. See margin. The word is probably old Persian, though it does not occur in the cuneiform inscriptions. Some derive it from a root “to fear.” See the introduction to the Book of Ezra, first note.

A priest with Urim and with Thummim - See (Exodus 28:30) note. According to the rabbinical writers, the second temple permanently lacked this glory of the first. Zerubbabel, it would seem by the present passage , expected that the loss would be only temporary.