also halleluiah, 1530s, from Hebrew hallalu-yah "praise ye Jehovah," from hallalu, plural imperative of hallel "to praise" also "song of praise," from hillel "he praised," of imitative origin, with primary sense being "to trill." Second element is yah, shortened form of Yahweh, name of God. Replaced variant formation alleluia (12c.).
praise ye Jehovah, frequently rendered "Praise ye the LORD," stands at the beginning of ten of the psalms (106, 111-113, 135, 146-150), hence called "hallelujah psalms." From its frequent occurrence it grew into a formula of praise. The Greek form of the word (alleluia) is found in Rev. 19:1, 3, 4, 6.
Hebrew liturgical expression meaning "praise ye Yah" ("praise the Lord"). It appears in the Hebrew Bible in several psalms, usually at the beginning or end of the psalm or in both places. In ancient Judaism it was probably chanted as an antiphon by the Levite choir. In the New Testament it appears only in Revelation 19, where it occurs four times. It was translated in the Septuagint (Jewish Greek version of the Bible made in the pre-Christian period) and became "alleluia" in the Vulgate (4th-century Christian Latin version). The early Christians adopted the expression in their worship services, and it appeared in Orthodox, Roman Catholic, Anglican, and some Protestant liturgies and in hymns.