Sacrament from the
tabernacle before the exposition, and replace it therein after the
Benediction. The office of assistant appears to have been instituted as
a measure of precaution against the danger which might result from the
near approach of the deacon's vestments to the lights, in case he took
down the ostensorium, or to guard against other inconveniences. But
there is no reason why the assistant should present the ostensorium to
the celebrant when the deacon and sub-deacon are present.

We should remark, in the next place, that, according to the text of the
_Ceremoniale Episcoporum_, and of the _Instructio Clementina_, the
priest, after receiving the humeral veil, mounts the steps without the
ministers, and himself takes the ostensorium. Authors prescribe that the
deacon and sub-deacon should kneel on the highest step, and support the
celebrant's cope during the benediction. In their absence, this is done
by the master of ceremonies, or two clerks. When the benediction has
been given, the priest having completed the circle, places the Blessed
Sacrament in the corporal, genuflects, and descends with the sub-deacon,
whilst the deacon restores the Blessed Sacrament to the tabernacle,
unless this be done by the assistant priest, in which case the deacon
descends with the celebrant and the sub-deacon. According to Baldeschi,
the veil is removed from the celebrant when he genuflects in the
predella, after having given the benediction.

The rubric of the _Ceremoniale Episcoporum_ (l. ii. c. xxiii., n. 27)
makes no mention of the assistant priest, supposes that the bishop
himself takes the ostensorium from the altar, and expressly declares
that he himself replaces it on the corporal.

"Accedat ad altare et accepto tabernaculo seu ostensorio cum
sanctissimo Sacramento, illud ambabus manibus velatis elevatum
tenens, vertens se ad populum, cum illo signum crucis super populum
ter faciet nihil dicens. Quo facto iterum deponet sanctissimum
Sacramentum super altare".

We read in the _Instructio Clementina_ (Sec. xxxi.): "The celebrant, on
his knees, will take the humeral veil, and ascending the altar without
attendants, after due reverence, will take the ostensorium in his hands,
which are covered with the extremity of the humeral veil, and with it
will give the benediction to the people; and having replaced the Blessed
Sacrament on the corporal, will descend, and remain on his knees in his
place.