The - treasure house - גנזיא ginzaiya . This is a Persian word, gunji, a treasury.
There is a great deal of good sense and candour in this letter. Nothing of passion or prejudice appears in it. They laid before the king a fair statement without any attempt to prejudice his mind, and gave him those directions which were most likely to lead him to the truth, and to form a correct judgment on a business which, however it issued, must be of considerable importance to the state. God was in all this business; he was now giving an additional proof of his continued regard for a disobedient people, whom, though he had punished in his justice, he had spared in his mercy.
Let there be search made at Babylon - They perhaps doubted whether proof of the decree of Cyrus remained in the archives. The Pseudo-Smerdis had had the records in his power for seven months; and, when he reversed the policy of his predecessors, might have been expected to destroy their edicts. The decree was not found at Babylon, the most natural place for it, but in the provincial capital of Ecbatana, which Tatnai and his friends had not asked Darius to have searched (see Ezra 6:2).