Charles Ellicott Commentary Leviticus 16:23

"And Aaron shall come into the tent of meeting, and shall put off the linen garments, which he put on when he went into the holy place, and shall leave them there:" — Leviticus 16:23 (ASV)

Shall come into the tabernacle of the congregation. —Better, shall come into the tent of meeting. This was the fourth time that the high priest entered into the Holy of Holies on the Day of Atonement. The object of his going into the most Holy was to fetch the censer and the incense cup which he had left between the two staves . To do this he had again to bathe, which always accompanied the change of garments, and to put on his white robes. As it was no part of the actual service, but was simply a necessary act subsequent to the service, it is not fully described in the text. This was the last act on the Day of Atonement which the high priest performed in his white robes.

And shall leave them there. —The robes were now deposited in a chamber in the sanctuary especially set apart for this purpose, and the high priest was never allowed to minister in them again.