holy of holies 
noun
1The inner chamber of the sanctuary in the Jewish Temple in Jerusalem, separated by a veil from the outer chamber. It was reserved for the presence of God and could be entered only by the High Priest on the Day of Atonement.What did we read about when we read from the Torah and the prophets on that holy of holies of Jewish time?...
- After the priests had established the ark of the covenant in the holy of holies, a cloud filled the Temple, and the glory of God's presence was so powerful that the priests were overwhelmed.
- He went into the temple and ate the bread in the holy of holies, that no person is to touch.
1.1A place regarded as most sacred or special: I knocked at the door and was admitted by Ms Brown to the holy of holies...
- Do you have your sacred space, where you build your stuff, your holy of holies?
- For Holmes and Greene, this was an awe-inspiring event - a visit to the holy of holies, the inner sanctum, the behind-the-scenes epicenter of New England mineral collecting.
- She stood for five days in endless queues before managing to enter the holy of holies - the Department of Welfare offices in Deals House.