Atsereth refers to a sacred assembly or solemn gathering — specifically the closing assembly at the end of major feast seasons. The word appears 11 times and is used for the assembly on the 8th day of Tabernacles (Leviticus 23:36) and the closing day of Passover/Unleavened Bread (Deuteronomy 16:8). It may derive from atsar (to restrain/hold back), suggesting a gathering where regular work is restrained.
The atsereth functioned as the sacred conclusion to Israel's great festivals — a 'holding together' of the community before God before returning to normal life. Jewish tradition identified Pentecost (Shavuot) itself with this word, and later rabbis called it 'Atsereth' as the climax of the Passover season. This concept — the solemn, joyful gathering at the end of a sacred season — anticipates the eschatological assembly of God's people at the end of the age. The gathering of the church, the 'great assembly' (Hebrews 12:23), fulfills what Israel's annual assemblies foreshadowed.