Hebrew Yom HaKippurim, "the Day of Atonement(s)." The most solemn day in the Jewish liturgical year, falling on the 10th of Tishri (September-October), nine days after Rosh Hashanah. Detailed in Leviticus 16 and 23:26-32. It was the one day each year when the high priest entered the Holy of Holies — and only after elaborate preparations. A day of complete rest, fasting, and affliction of the soul (Leviticus 16:29). Two goats were selected: one slaughtered as a sin offering for Israel, its blood sprinkled on the mercy seat; the other, the scapegoat (azazel), released into the wilderness bearing the sins of the people confessed over its head.
Yom Kippur is the OT sacrifice system's crowning annual act and the NT's master typological backdrop. Five observations. (1) The high priest's solitude. The entire nation's atonement rested on one man going alone into the Holy of Holies with blood. Hebrews 9 explicitly treats this as the type of Christ's work: "Christ has entered, not into holy places made with hands... but into heaven itself, now to appear in the presence of God on our behalf" (9:24). (2) Two goats, one salvation. The sacrificed goat's blood pictures payment of the penalty; the scapegoat released into the wilderness pictures the removal of sin from the camp. Christ accomplishes both in one act: His blood pays the penalty, and His resurrection bears sin away forever (Psalm 103:12 — "as far as the east is from the west"). (3) Once a year. Hebrews 10:1-4 argues that the very repetition of Yom Kippur proved its insufficiency. If it truly dealt with sin, it wouldn't have needed to be repeated. Christ's single offering did what a thousand years of Yom Kippurs could not: "he has perfected for all time those who are being sanctified" (Hebrews 10:14). (4) Afflict your souls (Leviticus 16:29-31). Yom Kippur is fast-and-prayer day, the biblical template for corporate repentance. Not every day is that day, but the Church should have such days. (5) Still observed. Modern Jews continue Yom Kippur but without temple, priesthood, or sacrifice — waiting for the redemption that Messiah has already brought.