ChristianAnswers.Net WebBible Encyclopedia
Meaning: 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.