APODIPNON (ἀπόδειπνον). - In churches of the Byzantine rite, it is a divine office intended to implore blessing during sleep, originating in the monasteries of the East. It arose after the establishment of the nocturnal and vesperal prayers and of the three minor hours, deriving from the aspiration of the religious soul to close the day by commending itself to the Lord and consecrating its rest to Him. Such is the meaning of question 37 in the longer rules of s. Basilio, composed between 358 and 362, which for the first time mentions this prayer, with the prescription of Psalm 90, retained to the present day.
In the Byzantine rite a distinction is made between the ordinary a. and the great a., recited during the great Lent and
on certain vigils of the year. The form of the latter would be older than the simple form, which is, as it were, a summary of it and represents one third of II. The general outline of the a. is as follows: 1) Introductory prayers; 2) Invitation to three psalms; 3) Doxology (Gloria in excelsis with its symbolism); 4) Creed; 5) Trisaghion, with appropriate troparia; 6) Kyrie eleison (40 times), with prayers and contaghion or troparia of the Virgin; 7) Dismissal and forgiveness; 8) Final litanies and blessing. During Easter week the a. consists of certain passages taken from the office of the feast. In monasteries the a. is recited in the narthex, and in the laura each calogero recites it in his cell.