Hallelujah (ˌhæləˈluːjə ; hallū-Yāh, Modern halləlū-Yah) is an interjection from the Hebrew language, used as an expression of gratitude to God. The term is used 24 times in the Hebrew Bible (in the book of Psalms), twice in deuterocanonical books, and four times in the Christian Book of Revelation.
The phrase is used in Judaism as part of the Hallel prayers, and in Christian prayer, where since the earliest times it is used in various ways in liturgies, especially those of the Catholic Church, the Lutheran Churches and the Eastern Orthodox Church, the three of which use the Latin form alleluia which is based on the alternative Greek transliteration.
Hallelujah is a transliteration of הַלְלוּ יָהּ (hallū yāh), which means "praise ye Jah!" (from , "praise ye!" and , "Jah".) The word hallēl in Hebrew means a joyous praise in song. The second part, Yah, is a shortened form of YHWH (Yahweh or Jehovah in modern English).
In the Hebrew Bible hallelujah is actually a two-word phrase, hal(e)lu-Yah, and not one word. The first part, hallu, is the second-person imperative masculine plural form of the Hebrew verb hillel. The phrase "hallelujah" translates to "praise Jah/Yah", though it carries a deeper meaning as the word halel in Hebrew means a joyous praise in song, to boast in God.
The second part, Yah, is a shortened form of YHWH, the name of the national god of Israel. The name ceased to be pronounced in Second Temple Judaism, by the 3rd century BC due to religious beliefs. The correct pronunciation is not known, however, it is sometimes rendered in non-Jewish sources as "Yahweh" or "Jehovah". The Septuagint translates Yah as Kyrios (the ), because of the Jewish custom of replacing the sacred name with "Adonai", meaning "my Lord".
In the Hebrew reads kol han'shamah t'halel yah hallu-yah; the first "hallel" and "yah" in this verse are two separate words, and the word "yah" is translated as "the LORD", or "YHWH". In 148:1 the Hebrew says hallu Yah hallu eth-YHWH, notably including both the shortened Yah and the full name of YHWH.