The word ????????>? occurs in the LXX, answering to the Hebrew word halal in the Psalms translated 'praise ye the Lord.' It is an ascription of praise to God. In Re 19:1,3-4,6 the praise is heard in heaven: through mercy the saint learns to raise his Hallelujah on his way thither.
After this I heard something like the loud voice of a vast multitude in heaven, saying: Hallelujah! Salvation, glory, and power belong to our God,
A second time they said: Hallelujah! Her smoke ascends forever and ever! Then the 24 elders and the four living creatures fell down and worshiped God, who is seated on the throne, saying: Amen! Hallelujah!
Then I heard something like the voice of a vast multitude, like the sound of cascading waters, and like the rumbling of loud thunder, saying: Hallelujah-because our Lord God, the Almighty, has begun to reign!
Holman Christian Standard Bible®, Copyright © 1999, 2000, 2002, 2003, 2009 by Holman Bible Publishers.