On matters liturgical, St. Francis of Assisi.
Epistola ad clericos
Let us all consider, O clerics, the great sin and ignorance of which some are guilty regarding the most holy Body and Blood of our Lord Jesus Christ and His most holy Name and the written words of consecration. For we know that the Body cannot exist until after these words of consecration. For we have nothing and we see nothing of the Most High Himself in this world except [His] Body and Blood, names and words by which we have been created and redeemed from death to life.
But let all those who administer such most holy mysteries, especially those who do so indifferently, consider among themselves how poor the chalices, corporals, and linens may be where the Body and Blood of our Lord Jesus Christ is sacrificed. And by many It is left in wretched places and carried by the way disrespectfully, received unworthily and administered to others indiscriminately. Again His Names and written words are sometimes trampled under foot, for the sensual man perceiveth not these things that are of God. Shall we not by all these things be moved with a sense of duty when the good Lord Himself places Himself in our hands and we handle Him and receive Him daily? Are we unmindful that we must needs fall into His hands?
Let us then at once and resolutely correct these faults and others; and wheresoever the most holy Body of our Lord Jesus Christ may be improperly reserved and abandoned, let It be removed thence and let It be put and enclosed in a precious place. In like manner wheresoever the Names and written words of the Lord may be found in unclean places they ought to be collected and put away in a decent place. And we know that we are bound above all to observe all these things by the commandments of the Lord and the constitutions of holy Mother Church. And let him who does not act thus know that he shall have to render an account therefore before our Lord Jesus Christ on the day of judgment. And let him who may cause copies of this writing to be made, to the end that it may be the better observed, know that he is blessed by the Lord.
Attendamus, omnes clerici, magnum peccatum et ignorantiam, quam quidam habent super sanctissimum corpus et sanguinem Domini nostri Jesu Christi et sacratissima nomina et verba eius scripta, quae sanctificant corpus. Scimus, quia non potest esse corpus, nisi prius sanctificetur a verbo. Nihil enim habemus et videmus corporaliter in hoc saeculo de ipso Altissimo, nisi corpus et sanguinem, nomina et verba, per quae facti sumus et redempti de morte ad vitam (1 Joa 3,14). Omnes autem illi qui ministrant tam sanctissima ministeria, considerent intra se, maxime hi qui indiscrete ministrant, quam viles sint calices, corporalia et linteamina, ubi sacrificatur corpus et sanguis Domini nostri. Et a multis in locis vilibus relinquitur, miserabiliter portatur et indigne sumitur et indiscrete aliis ministratur. Nomina etiam et verba eius scripta aliquando pedibus conculcantur; quia animalis homo non percipit ea quae Dei sunt (1 Cor 2,14). Non movemur de his omnibus pietate, cum ipse pius Dominus in manibus nostris se praebeat et eum tractemus et sumamus quotidie per os nostrum? An ignoramus, quia debemus venire in manus eius? Igitur de his omnibus et aliis cito et firmiter emendemus; et ubicumque fuerit sanctissimum corpus Domini nostri Jesu Christi illicite collocatum et relictum, removeatur de loco illo et in loco pretioso ponatur et consignetur. Similiter nomina et verba Domini scripta, ubicumque inveniantur in locis immundis, colligantur et in loco honesto debeant collocari. Et scimus, quia haec omnia tenemur super omnia observare secundum praecepta Domimi et constitutiones sanctae matris Ecclesiae. Et qui hoc non fecerit, sciat, se coram Domino nostro Jesu Christo in die iudicii reddere rationem (cfr. Mt 12,36). Hoc scriptum, ut melius debeat observari, sciant se benedictos a Domino Deo, qui ipsum fecerint exemplari.