To-morrow, Fr Rowe will be celebrating (from the Masses pro aliquibus locis) the Mass of All Holy Relics; while Dominicans using their traditional liturgy will offer up the Sacrifice in honour of St Martin de Porres (according to the new books, his feast has just been held on Monday the 3rd).
Mirabilis Deus in sanctis suis - "God is wonderful in His saints" (Ps 67:36): how true this is, is made manifest in the cult of relics.
The Epistle for All Holy Relics is taken from Ecclesiasticus xliv, 10-15: which ends Corpora ipsorum in pace sepulta sunt, et nomen eorum vivit in generationem et generationem. Sapientiam ipsorum narrent populi, et laudem eorum nuntiet Ecclesia. ("Their bodies in peace are buried, and their names have lived in generation and generation. Their wisdom let the peoples declare, and their praise let the Church proclaim.") As for the Gospel, it is from St Luke vi, 17-23, which announces Our Lord's healing ministry and the shorter, Lukan version of the Beatitudes; as He is the Saint of saints, the fact that omnis turba quærebat eum tangere: quia virtus de illo exibat, et sanabat omnes, "all the multitude sought to touch Him: for virtue went forth from Him and healed all" serves as the preëminent and all-surpassing exemplar of the power of all relics.
In the case of Christ, His sacred Humanity was and is the physical instrument of His Divinity, whereby he worked theandric acts (as Ps-Dionysius put it originally). In the case of His saints, they were and are united to Christ by grace as members of His Body Mystical; their bodies were temples of the Holy Ghost, and, sundered from their holy souls in death, remain venerable, remain by God's goodpleasure instruments whereby their glorious suffrages and merits may be piously invoked, whereby the Lord may deign to grant graces according to His Will, Who ever delighteth in working through secondary causes. It must not be forgotten, and indeed the Collect of the feast puts this in the first place, that the remains of the saints shall not moulder for ever, but are destined - as is all mortal flesh - to be one day reunited with the soul and rise incorruptible evermore: hence, relics may be said to venerated not so much for what they were, as for what they shall be - the glorified bodies of the saved. As is par excellence the Body of Christ in the Eucharist, so too in their lesser configurement to Him the remains of His hallowed servants are "a pledge of future glory", which we pray we may share.
If I had been asked to consider what passages would answer as readings and chants for this feast, I would have guessed IV Kings xiii, 20-21 (a corpse, upon touching the bones of the holy prophet Eliseus disciple of Elias, is restored to life) and also Acts v, 14-16 (the new believers laid the sick on the streetside, that the shadow of St Peter fall on them as he passed; and they were all cured) and xix, 11-12 ("and God worked more than the usual miracles [!] by the hand of Paul" - even handkerchiefs that had but touched him effected cures). If such be the effect of the shadow and of cloths touched to Princes of the Apostles, what virtue would not their sacred relics possess? - as shewn by the vivifying influence of the mortal remains of a prophet: all of these results being images of the greater spiritual healing and restoration to supernatural life that due veneration of relics can work in souls, by the grace of God.
(Recall that a first-class relic is an actual part of the physical remains of a saint, as the body of Bl Pier Giorgio Frassati, brought from Turin to Sydney for WYD, during which I venerated it along with so many others; a second-class relic, some item belonging to them, as for instance a piece of a religious habit worn by St Thérèse; a third-class, something merely touched to a first-class relic, as a piece of cloth touched to the relics of St Dominic.)
The Collect for All Sacred Relics:
Auge in nobis, Domine, resurrectionis fidem, qui in Sanctorum tuorum Reliquiis mirabilia operaris: et fac nos immortalis gloriæ participes; cujus in eorum cineribus pignora veneramur. Per...(Increase in us, Lord, faith in the resurrection, Who in the Relics of Thy Holy Ones workest wonders: and make us partakers of the immortal glory, whose pledge we revere in their ashes. Through...)