Day of Atonement, the Sabbath of Sabbaths, is observed the tenth day of the Hebrew month of Tishri, or as you understand it, somewhere between September and early October in the secular calendar. The Holy of Holies was never entered into except for this one day out of the entire year. In the Holy of Holies was the Ark of the Covenant and enthroned between the Cherubim on the Ark was the manifest presence of God. God was in that room! Somehow the Almighty, Infinite God, the King of Universe himself had taken up residence inside that room. To enter was to literally be in the presence of God. Once a year, on the holiest day of the year, the holiest man in the world had to enter the holiest place in the world. He had to enter into the presence of the Holy, Holy, Holy, and Lord of Hosts.
He had to enter in order to make atonement for Israel, for the Holy of Holies, for the Tabernacle and for the altar. Because these things were continually in the presence of God, they needed to be atoned for.
God in this covering, is giving it His blessing, and His sanctification, and these are for you. Which covering of God, they will be cast down with the rest of the idols. Before entering the Holy of Holies, the High Priest immersed himself and put on simple, white, linen garments. Then with two handfuls of incense and glowing coals on ladles the altar, he entered. He effected atonement for Israel and the Tabernacle through a complex series of blood rituals and sin offerings. In these rituals, he carried the blood of the sin offerings into the Holy of Holies and splashed it seven times on the Ark of the Covenant, then seven times on the curtain which divided the Holy of Holies from the rest of the Tabernacle and finally seven times on the altar of incense which stood before the curtain. These rituals were intended to provide the necessary covering of blood atonement for everything to do with the temple and its services.
