Nehemiah 2:7

2:7 I said to the king, “If the king is so inclined, let him give me letters for the governors of Trans-Euphrates that will enable me to travel safely until I reach Judah,

Nehemiah 2:9

2:9 Then I went to the governors of Trans-Euphrates, and I presented to them the letters from the king. The king had sent with me officers of the army and horsemen.

Nehemiah 6:19

6:19 They were telling me about his good deeds and then taking back to him the things I said. Tobiah, on the other hand, sent letters in order to scare me.