Reservation
The celebrant places the consecrated hosts not consumed during the communion of the faithful into the tabernacle where they are reserved especially for the sick
Ablutions
The subdeacon or server pours wine into the empty chalice, while the celebrant says:
Quod ore sumpsimus, Domine, pura mente capiamus: et de munere temporali fiat nobis remedium sempiternum.
Grant, O Lord, that what we have taken with our mouth, we may receive with a pure mind: and that from a temporal gift it may become for us an eternal remedy.
The celebrant goes to the Epistle side of the altar to cleanse his fingers and the chalice. While the subdeacon or server pours (a little wine and) water into the chalice over his fingers, he prays:
Corpus tuum, Domine, quo sumpsi, et Sanguis quem potavi,adhaereat visceribus meis: et praesta, ut in me non remaneat scelerum macula, quem pura et sancta refecerunt sacramenta: Qui vivis et regnas in saecula saeculorum. Amen.
May your Body, O Lord, which I have received and your Blood which I have drunk, cleave to my inmost parts, and grant that no stain of sin may remain in me, whom these pure and holy sacraments have refreshed. Who lives and reigns world without end. Amen.
The ministers, or the server, take the chalice veil to the Gospel side and the Missal to the epistle side of the alter. (At Low Mass, the server then kneels on the lowest step at the left side.)
Post-Communion Prayer
The celebrant, at Low Mass recites the Communion antiphon (proper to the Mass) and then says:
Dominus vobiscum.
r. Et cum spiritu tuo.
The Lord be with you.
r. And with your spirit.
He then recites the Post-Communion prayer (proper to the Mass).
After the conclusion, the server (and the congregation) answer: Amen.