Albert Barnes Commentary Ezra 10:6

"Then Ezra rose up from before the house of God, and went into the chamber of Jehohanan the son of Eliashib: and [when] he came thither, he did eat no bread, nor drink water; for he mourned because of the trespass of them of the captivity." — Ezra 10:6 (ASV)

The "chamber of Johanan" was probably one of those attached externally to the temple (see 1 Kings 6:5–6). Eliashib was the grandson of Jeshua (Ezra 3:2), and was high priest under Nehemiah (Nehemiah 3:1). He could assign chambers in the temple to whomever he pleased .