The word "them" refers to the nine leaders and two teachers written about in [Esra 8:16](./16.md). Alternate translation: "Next I sent those men to Iddo" (See: [[rc://en/ta/man/translate/figs-explicit]])
The words "that is" introduces what he told them to say. Alternate translation: "I told them to tell Iddo ... to send us servants for the house of God"