Today we remember the miracle of the stigmata of St. Francis. You can read the story here.
Below is an instruction given by St. Francis to clerics on proper reverence for the Eucharist and the Altar.
ON REVERENCE FOR THE LORD'S BODY AND ON THE CLEANLINESS OF THE ALTAR.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. 1 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 therefor 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.