A truly fitting prayer for Corpus Christi – and for any Thursday of the year – is the Respice, Domine which was composed by St. Cajetan. The Raccolta listed the following indulgences for this prayer:
i. A plenary indulgence to all the faithful who, being contrite, and having confessed and gone to Communion on the first Thursday in the month, shall on that day visit the Blessed Sacrament, either at Exposition time or when enclosed in the Tabernacle, and say there the following prayer, Respice, Domine.
ii. An indulgence of seven years and seven quarantines every Thursday in the year, to all who, after Confession and Communion, shall say the above prayer, on their knees, before the Blessed Sacrament.
iii. An indulgence of 100 days for saying it, with contrite heart, before the Blessed Sacrament, on any day whatever.
Look down, O Lord, from Thy sanctuary, and from Heaven Thy dwelling-place on high, and behold this sacred Victim which our great High-Priest, Thy holy Child, our Lord Jesus, offers up to Thee for the sins of This brethren; and be appeased for the multitude of our transgressions. Behold the voice of the Blood of Jesus, our Brother, cries to Thee from the Cross. Give ear, O Lord! be appeased, O Lord! hearken, and do not tarry for Thine own sake, O my God, for Thy Name is invoked upon this city and upon Thy people; and deal with us according to Thy mercy. Amen.
Respice, Domino, de sanctuario tuo et de excelso coelorum habitaculo, et vide hanc sacrosanctam Hostiam, quam Tibi offert magnus Pontifex noster Sanctus Puer tuus Dominus Jesus pro peccatis fratrum suorum; et esto placabilis super multitudinem malitiae nostrae. Ecce vox Sanguinis fratris nostri Jesu clamat ad Te de Cruce. Exaudi, Domine; placare, Domine; attende, et fac, ne moreris propter temetipsum, Deus meus, quia nomen tuum invocatum est super civitatem istam, et super populum tuum; et fac nobiscum secundum misericordiam tuam. Amen.