Question: "An liceat sacerdoti accipere ostensorium per manus diaconi istud ex altari acceptum porrigentis, ut populo benedictio impertiatur, et post benedictionem remittere ostensorium diacono, qui super altare deponet, prout fit in nonnullis ecclesiis? Vel ipsemet sacerdos debeat accipere ostensorium ex altari, et data benedictione, super altare deponere, sicut expresse docent Gavantus in rubrica Miss. part. vi., tit. xiii., n. 7; Merati in Gavantum", etc.
Answer: "Quoad primam partem, licere etiam ex praxi ecclesiarum Urbis; quoad secundam partem, provisum in primo".
Hence it appears that the Instructio Clementina and the Caeremoniale have been too rigorously interpreted by old authors. We are at liberty to choose whichever of the two usages may agree better with the arrangements of the altar, and may be more easy to carry out. This is the common opinion of recent authors, and is founded on Roman usage and on the decision just cited. In addition, if the deacon is to receive the ostensorium from the priest's hands, the priest is not bound to complete the circle: he returns towards the altar, on the epistle side, where the deacon is. This follows from the decree of the 21st March, 1676, No. 2776:
Question: "An in benedicendo populum cum sanctissimo Sacramento sit servandus modus infrascriptus: Cum sacerdos stat ante populum, ostensorium ante pectus tenet, tum elevat illud decenti mora non supra caput, sed tantum usque ad oculos, et eodem modo illud demittit infra pectus, mox iterum recte illud attollit usque ad pectus, et deinde ad sinistrum humerum ducit, et reducit ad dexterum, et rursus ante pectus reducit, ibique aliquantulum sistit quasi peracta ad omnes mundi partes cruce, eam etiam venerandam omnibus praebet: tunc gyrum perficiens, collocat ostensorium super altare?"
Answer: "Si placet, potest observare supradictum modum.... Sin minus, servandus est modus dispositus in Caer. Ep., l. ii., c. xxxiii., ubi requiritur tantummodo ut cum eodem SS. Sacramento celebrans producat signum crucis super populum".
It is now easy to fix the ceremonies to be observed in cases where the deacon presents the ostensorium to the priest, and receives it from him after the benediction. First, the celebrant kneels in receiving the Blessed Sacrament from the deacon, and the deacon, when he receives it from the celebrant. This is a standing liturgical rule—the rubric of the Missal for Holy Thursday says:
"Finita Missa ... fit processio.... Celebrans indutus pluviali albo ... in medio genuflexus ... accepto calice cum Sacramento de manu diaconi stantis.... Cum autem ventum fuerit ad locum paratum diaconus genuflexus a sacerdote stante accipit calicem cum Sacramento".
In the Cer. Ep. (l. ii., c. xxiii., n. 12 et 13):
"Diaconus assistens ... capit SS. Sacramentum de altari, et illud, stans, offert episcopo genuflexo. Cum pervenerit ad sacellum ubi Sacramentum deponi debet ... cum erit episcopus ante supremum gradum altaris, diaconus accipiet de manu ipsius stantis SS. Sacramentum genuflexus".
In the rubric for the procession of Corpus Christi (ibid., c. xxxiii., nos. 20 et 24):