While many are familiar with St. Francis of Assisi's life of poverty, few know that he was an ardent promoter of devotion to the Eucharist.
He firmly believed that Jesus was truly and substantially present under the appearance of bread and wine at Mass.
With this in his mind, he always sought to give Jesus in the Eucharist his utmost respect and devotion.
If St. Francis visited a church and saw that it was dirty, he would get out a broom and sweep it clean!
This Eucharistic devotion extended to the precious vessels used at Mass. He wrote in a letter to priests explaining why they should use high quality chalices and tabernacles.
He reiterated this point in his Testament.
St. Francis loved Jesus dearly and spent the rest of his life offering his every action to him. With a burning fire of love in his heart, he couldn't stand to watch Jesus being treated poorly.
His desire to treat the Eucharist with such respect only makes sense when viewed through the lens of the Real Presence of Jesus. If Jesus is truly present under the appearance of bread and wine, then St. Francis believed that anything that contained the Eucharist should be fit for a king.