The "Holy of Holies" is the innermost sanctuary of the ancient Temple in Jerusalem, where the presence of God was believed to dwell. It was separated from the rest of the temple by a thick curtain and could only be entered by the High Priest once a year on the Day of Atonement, known as Yom Kippur. This sacred space housed the Ark of the Covenant, which contained the tablets of the Ten Commandments. The Holy of Holies symbolized the ultimate connection between God and the people of Israel, representing divine holiness and the importance of atonement.