Liturgical Handbook of the Russian Orthodox Church Abroad

In parishes where there is no Deacon, the Priest will assume all the Deacon’s litanies during the All-Night Vigil. In so doing, he will follow the general practice of departing the Altar via the north Deacon’s door and intoning the litanies upon the amvon (with his head covered, if he has been awarded a head covering or, if a monastic, wears one by obedience), and will then return to the Altar via the south Deacon’s door after the exclamation of the Litany. However, there are two exceptions to this rule:

Firstly, whenever the Royal Doors are opened and the Priest is vested in his phelon, he will intone the litany from within the Altar, standing before the Holy Table. (Thus, for example, at the two concluding litanies of Matins, following the Great Doxology at which the Royal Doors are opened, the Priest being vested in phelon.)

Secondly, the little litany after the Ninth Ode of the Matins canon is intoned from within the Altar, even though the Priest is not vested in phelon and the Royal Doors are closed. This is, by tradition, in order that the exclamation of that litany can be heard coming from within the Altar rather than without it: for this exclamation (‘For all the powers of heaven…’) is the proclamation of the angelic ranks joining in the praise of the Saviour, and the Altar is symbolic of the heavenly realm.