38. chambers … entries—literally, "a chamber and its door."
by the posts—that is, at or close by the posts or columns.
where they washed the burnt offering—This does not apply to all the gates but only to the north gate. For Le 1:11 directs the sacrifices to be killed north of the altar; and Eze 8:5 calls the north gate, "the gate of the altar." And Eze 40:40 particularly mentions the north gate.