Charles Ellicott Commentary Ezra 5:3

"At the same time came to them Tattenai, the governor beyond the River, and Shethar-bozenai, and their companions, and said thus unto them, Who gave you a decree to build this house, and to finish this wall?" — Ezra 5:3 (ASV)

Tatnai, governor on this side the river. —Satrap, or Pechah, of the entire province of Syria and Phoenicia, and therefore with a jurisdiction over Judea, and over Zerubbabel its Pechah or sub-Satrap. What Shimshai was to the Samaritan Pechah, Rehum, Shethar-boznai seems to be to Tatnai—his secretary.

Who hath commanded you? —It is obvious that the overthrow of Smerdis, the Magian hater of Zoroastrianism and destroyer of temples, had encouraged the builders to go on without fearing interference from the Court of Darius. Moreover, the two prophets had made their duty too plain to be deferred. Still, the decree of the preceding chapter had never been expressly revoked.