Liturgical Handbook of the Russian Orthodox Church Abroad

A certain degree of variation is permitted on this question, for practical reasons.

Technically speaking, the covering of the gifts (the conclusion of the Proskomedia) takes place during the Sixth Hour. The Deacon comes to the Table of Oblation with the censer as the psalms of the Sixth Hour are being read, takes the blessing for the incense, and then holds the censer while the Priest covers the gifts and they together say the concluding prayers of the Proskomedia. The Priest takes the censer and censes the gifts, then returns it to the Deacon who proceeds to make the full censing of the temple customary to the Sixth Hour (or, if the Priest serves alone, he does all this himself).

This practice — which presumes that the Priest begins the Proskomedia at the beginning of the Hours and performs the rite and commemorations throughout them — is not always practical in parishes, where it is regularly the custom for the Priest to hear confessions during the Hours and who therefore serves the Proskomedia before the Hours begin. In these situations (which, again, are entirely normal in parish life), it is better not to leave the gifts uncovered for so long a period in the Priest’s absence, in order to cover them only at the Sixth Hour. It is better in these circumstances that the Priest entirely conclude the Proskomedia — including the covering and censing of the gifts — before the Hours begin. Then, at the Sixth Hour, the Deacon (or the Priest) censes the whole temple in the usual way.

Differing rules apply when serving the Proskomedia before an hierarchical service. These are described elsewhere in the present Handbook.