This is somewhat belated, as the feast of Corpus Christi was yesterday, but I believe it used to have an Octave, so traditionally we should still be celebrating the feast. The following excerpts constitute some of the lessons for the office of Matins for this feast in the Tridentine breviary, as found here. A more complete presentation of St. Thomas' work in composing the office, including more excerpts in the lessons, may be found here. This exemplifies St. Thomas' profoundly liturgical and Eucharistic mysticism. He was not merely the rational thinker whom he is normally made out to be. He was motivated by an intense piety, which can be seen in this, probably his greatest masterpiece, the office of Corpus Christi.
From the Sermons of St Thomas of Aquino.
17th or 57th of his Opuscula, or Lesser Works.
The immeasurable benefits, which the goodness of God hath bestowed on Christian people, have conferred on them also a dignity beyond all price. " For what nation is there so great, who hath gods so nigh unto them, as the Lord, our God, is" unto us? Deut. iv. 7. The Only-begotten Son of God, being pleased to make us " partakers of the Divine nature," 2 Pet. i. 4, took our nature upon Him, being Himself made Man that He might make men gods. And all, as much of ours as He took, He applied to our salvation. On the Altar of the Cross He offered up His Body to God the Father as a sacrifice for our reconciliation He shed His Blood as the price whereby He redeemeth us from wretchedness and bondage, and the washing whereby He cleanseth us from all sin. And for a noble and abiding memorial of that so great work of His goodness, He hath left unto His faithful ones the Same His very Body for Meat, and the Same His very Blood for Drink, to be fed upon under the appearance of bread and wine.
How precious a thing then, how marvellous, how health-giving, how furnished with all dainties, is the Supper [of the Lord !] Than His Supper can anything be more precious ? Therein there is put before us for meat, not, as of old time, the flesh of bulls and of goats, but Christ Himself, our very God. Than this Sacrament can anything be more marvellous ? Therein it cometh to pass that bread and wine are bread and wine no more, but in the stead thereof there is the Body and there is the Blood of Christ; that is to say, Christ Himself, Perfect God and Perfect Man, Christ Himself is there, under the appearance of a little bread and wine. His faithful ones eat Him, but He is not mangled ; nay, when [the veil which shroudeth Him in] this Sacrament is broken, in each broken piece thereof remaineth whole Christ Himself, Perfect God and Perfect Man. All that the senses can reach in this Sacrament, [look, taste, feel, smell, and the like, all these] abide of bread and wine, but the Thing is not bread and wine. And thus room is left for faith ; Christ Who hath a Form That can be seen, is here taken and received not only unseen, but seeming to be bread and wine, and the senses, which judge by the wonted look, are warranted against error.
Than this Sacrament can anything be more health - giving Thereby are sins purged away, strength renewed, and the soul fed upon the fatness of spiritual gifts. This Supper is offered up in the Church both for the quick and dead it was ordained to the health of all, all get the good of it. Than this Sacrament can anything be more furnished with dainties The glorious sweetness thereof is of a truth such that no man can fully tell it. Therein ghostly comfort is sucked from its very well - head. Therein a memorial is made of that exceeding great love which Christ showed in time of His sufferings. It was in order that the boundless goodness of that His great love might be driven home into the hearts of His faithful ones, that when He had celebrated the Passover with His disciples, and the last Supper was ended, the Lord " Jesus, knowing that His hour was come that He should depart out of this world unto the Father, having loved His own which were in the world, He loved them unto the end," John xiii. 1, and instituted this Sacrament, this Sacrament, the everlasting forth - " showing of His death until He come " again, 1 Cor. xi. 26, this Sacrament, the embodied fulfilment of all the ancient types and figures, this Sacrament, the greatest miracle which He ever wrought, and the one mighty joy of them that now have sorrow, till He shall come again, and their heart shall rejoice, and their joy no man take from them. John xvi. 22.