One Text, Many Occasions, No Single Author

Kaddish is not one fixed text used on one occasion but a family of closely related versions distinguished by where in the service they occur and by a few added lines: the Half Kaddish marks a transition between sections of the liturgy, the Full or Rabbinic Kaddish follows study of rabbinic texts and includes a line absent from the others, and the Mourner's Kaddish, the version most familiar outside observant communities, is recited by mourners for eleven months after a parent's death and on each subsequent anniversary. These variants developed gradually, and the earliest complete texts of any of them appear only in medieval prayer books, considerably later than the core Aramaic language, which belongs to the Talmudic period.

The fact most commonly noted about Kaddish, and the one hardest to explain to someone encountering it for the first time, is that its text says nothing at all about death, mourning or the deceased: it is entirely praise of God, the same doxological content whichever version is being recited, with no reference to grief, memory or loss anywhere in the Aramaic. Rabbis explaining the custom generally locate its adoption as a mourner's prayer, attested from around the thirteenth century, in the theological point that grief is met not with a text about loss but with public affirmation of God's greatness precisely at the moment loss might tempt a mourner to doubt it, so that the absence of any mention of death in the words is treated not as an oversight but as the entire pedagogical point of assigning this text to mourners rather than a text actually about dying.