Psalm 104 (Psalm 103 in Septuagint based translations) is a poem in the Bible. It begins:

Bless the Lord, O my soul.

Some scholars have noted similarities between this psalm and the Great Hymn to the Aten.

Its main liturgical usage in the Eastern Orthodox Church is near the beginning of vespers or evening prayers. It is typically either chanted by a reader or sung by the choir using one of many musical arrangements of the Psalm which have been composed over the years.

Psalm 104 is chanted at the end of Jewish services on certain occasions, such as the New Moon (Rosh Chodesh), though customs vary. "It has been declared that it is worthwhile studying the Hebrew language for ten years in order to read Psalm 104 in the original."

Source

  Daily Prayer Book, Philip Birnbaum, 1949, p.465