In ancient Israel, the solemn assembly was a special occasion solemnizing the completion of a feast, or a penitential assembly of the people under threat of national disaster. It was marked by cessation from work and fasting or prayer.
The solemn assembly was the gathering and sanctifying of the community of Israel for a solemn occasion. It was used in the technical sense as the eighth day of the Feast of Booths (Lev. 23:36; Num. 29:35; Neh. 8:18) and the seventh day of Passover (Deut. 16:8). In both instances, the people were instructed to “do no work” on this day, for they were in a state of ritual holiness. At the dedication of the temple, Solomon proclaimed a solemn assembly on the eighth day, “for they had celebrated the dedication of the altar for seven days and the festival for seven days more” (2 Chron. 7:9). For a quite different purpose, Jehu ordered the people to “call an assembly in honor of Baal” (2 Kings 10:20). He used the occasion to complete his purge of Baal worshipers from the land of Israel by massacring those who had gathered.
In contrast to the above-mentioned feast days, the solemn assembly was also convened for special days of fasting. When a locust plague threatened the land, Joel exhorted Israel to “declare a holy fast; call a sacred assembly. Summon the elders and all who live in the land to the house of the Lord your God, and cry out to the Lord” (Joel 1:14; cf. 2:15).
Amos and Isaiah discredited these solemn assemblies sanction (Isa. 1:13; Amos 5:21) because the people did not do justice in the land. As Isaiah charged, “even if you offer many prayers … your hands are full of blood” (Isa. 1:15).
Although not mentioned in connection with the worship of the New Testament church, the concept of the solemn assembly has been retained in the Christian tradition, especially in the Ash Wednesday service of the liturgical churches. Some nonliturgical churches, particularly among Southern Baptists, are restoring the solemn assembly as a weekend emphasis on church renewal.