There was a chamber with a doorway by the portico in each of the inner gateways. There the burnt offering was to be washed.

1 Chronicles 28:12
The plans contained everything David had in mind for the courts of the house of the LORD, for all the surrounding rooms, for the treasuries of the house of God and of the dedicated things,

2 Chronicles 4:6
He also made ten basins for washing and placed five on the south side and five on the north. The parts of the burnt offering were rinsed in them, but the priests used the Sea for washing.

Nehemiah 13:5
and had prepared for Tobiah a large room where they had previously stored the grain offerings, the frankincense, the temple articles, and the tithes of grain, new wine, and oil prescribed for the Levites, singers, and gatekeepers, along with the contributions for the priests.

Nehemiah 13:9
Then I ordered that the rooms be purified, and I had the articles of the house of God restored to them, along with the grain offerings and frankincense.

Jeremiah 35:4
and I brought them into the house of the LORD, to a chamber occupied by the sons of Hanan son of Igdaliah, a man of God. This room was near the chamber of the officials, which was above the chamber of Maaseiah son of Shallum the doorkeeper.

Jeremiah 36:10
From the chamber of Gemariah son of Shaphan the scribe, which was in the upper courtyard at the opening of the New Gate of the house of the LORD, Baruch read from the scroll the words of Jeremiah in the hearing of all the people.

Ezekiel 40:17
Then he brought me into the outer court, and there were chambers and a pavement laid out all around the court. Thirty chambers faced the pavement,

Ezekiel 40:44
Outside the inner gate, within the inner court, were two chambers, one beside the north gate and facing south, and another beside the south gate and facing north.

Ezekiel 40:45
Then the man said to me: "The chamber that faces south is for the priests who keep charge of the temple,

Ezekiel 40:46
and the chamber that faces north is for the priests who keep charge of the altar. These are the sons of Zadok, the only Levites who may approach the LORD to minister before Him."

Ezekiel 41:10
and the outer chambers was twenty cubits wide all around the temple.

Ezekiel 42:13
Then the man said to me, "The north and south chambers facing the temple courtyard are the holy chambers where the priests who approach the LORD will eat the most holy offerings. There they will place the most holy offerings--the grain offerings, the sin offerings, and the guilt offerings--for the place is holy.

And the chambers and the entries thereof were by the posts of the gates, where they washed the burnt offering.