Date: April 05, 2021 11:53PM
When I Googled, a Wikipedia article titled "Holy of Holies" https://en.wikipedia.org/wiki/Holy_of_Holies
came up, containing two references to passages in the Talmud.
"...the Talmud suggests that repair crews were allowed inside as needed but were lowered from the upper portion of the room via enclosures so that they only saw the area they were to work on."
A good explanation of the Talmud: Talmud: https://en.wikipedia.org/wiki/Talmud