Tatnai, governor on this side the river. The title given to Tatnai is the same which is assigned to Zerubbabel, both in Ezra 6:7 and in Haggai (Haggai 1:1, Haggai 1:14, etc.), viz; pechah, which is a somewhat vague term of authority, translated sometimes "captain" (1 Kings 20:24; Daniel 3:2, Daniel 3:3, etc.
), sometimes "deputy (Esther 8:9; Esther 9:3), but generally, as here, "governor." The etymology is uncertain, but seems not to be Semitic. The respective rank of Tatnai and Zerub-babel is indicated, not by this term, but by what follows it.
Tatnai was pechah "beyond the river," i.e. governor of the whole tract west of the Euphrates; Zerubbabel was pechah of Judah only. A Greek writer would have called the one "satrap of Syria," the other "sub-satrap of Judaea."
It was the duty of Tatuai to watch the proceedings of his sub-satraps.