All the ancient authors agree with this view.
"Responso a choro Amen", says Bauldry (part. iv., art. iii., n. 33, 35, et 37), "celebrans, nihil addens, ascendit ad altare, genuflectit, et sine alterius ministerio accipit velatis manibus, ut prius, tabernaculum, vertens se ad populum ... benedicit ..., et gyrum perficiens, ostensorium collocat super altare.... Interim dum celebrans benedicit, ministri hinc inde [genuflexi], et inclinati facie versa ad sanctissimum Sacramentum, elevant partes anteriores pluvialis illius, quod et faciunt assistentes in pari casu.... Deposito sanctissimo Sacramento a celebrante super altare, ipse statim, genuflexione facta descendit ad secundum gradum ut prius, ubi genuflexus manet. Tum ponitur, si opus sit, scabellum ... pro diacono qui statim amoto velo ab eo pre subdiaconum vel caeremoniarium ascendit ad altare, ubi, facta genuflexione, reponit sanctissimum Sacramentum in tabernaculo".
Catalani, speaking of the benediction given by the bishop after the procession of the Blessed Sacrament, says (Cer. Ep., l. ii., c. xxviii., n. 27):
"Episcopus ... accepto tabernaculo sive ostensorio cum sanctissimo Sacramento, per se scilicet et sine alterius ministerio, illud ambabus manibus velatis elevatum tenens, vertens se ad populum, cum illo signum crucis super populum ter faciet.... Dataque benedictione, Episcopus deponet sanctissimum Sacramentum super altare".
Gavantus says the same (sect. i., part iv., tit. xii., n. 7):
"Ascendit (celebrans) ad altare, genuflectit, et ipsemet nullo diaconi ministerio accipit velatis manibus, ut prius, tabernaculum, benedicit cum eo populum ... nihil dicens, et gyrum perficiens reverenter reponit".
Merati thus comments on the passage:
"Celebrans ... ascendit ad altare ... et absque alterius ministerio accipit velatis manibus ostensorium".
Baldeschi gives the same directions.
But in spite of these authorities, it is customary in some churches for the deacon to ascend with the priest, to take the ostensorium, and present it to the celebrant, to receive it from the same after the benediction, and to replace it on the corporal. This usage is established in Rome, and has been confirmed by a decree of the 12th August, 1854, published in the Analecta.