The set-apart gathering of God's people called by divine command. Hebrew miqra qodesh (holy convocation) — named over the appointed feasts of Leviticus 23 (Sabbath, Passover, Pentecost, Day of Atonement, Tabernacles). Joel 1:14 and 2:15 use the same term in calls for national repentance: sanctify a fast, call a solemn assembly. A sacred assembly is not merely a meeting; it is the people of God responding to God's summons in His prescribed way, set apart from ordinary commerce and ordinary labor for the worship of the LORD. The New Testament continuation is the ekklesia — the called-out assembly of Christ. The Lord's Day gathering of the church is the modern sacred assembly, and treating it as optional social calendar item rather than as commanded covenant gathering inverts what Scripture is naming.