Jeremiah 13:1

Furthermore, this Paul said strongly that "the kingdom of God is not a matter of eating and drinking"—or abstinence from wine or meat—"but of righteousness, peace and joy in the Holy Spirit." Which of them goes around like Elijah wearing a sheepskin and a leather belt? Which of them wears no shoes and nothing but a piece of sackcloth like Isaiah? Or with nothing on but a linen loincloth, like Jeremiah?

The blessed John disdained sheep's wool because it savored of luxury; he preferred camel's hair and clothed himself in it, giving us an example of simple, frugal living. Incidentally, he also ate only honey and locusts, food that is sweet and with a spiritual significance. So it was that he prepared the way of the Lord and kept it humble and chaste. He fled from the false pretenses of the city and led a peaceful life in the desert with God, away from all vanity, boasting and servitude. How could he possibly have worn a purple mantle? Elijah used a sheepskin for his garment and girded it tight with a belt made of leather. Isaiah, another historic prophet, went "naked and without sandals" and often put on sackcloth as a garment of humility. If you protest and make mention of Jeremiah, he wore only a loincloth made of linen.

Yet such is the order of nature. While truth is always bitter, pleasantness waits upon evildoing. Isaiah goes naked without blushing, as a type of the captivity to come. Jeremiah is sent from Jerusalem to the Euphrates (a river in Mesopotamia) and leaves his girdle to be marred in the Chaldaean camp, among the Assyrians hostile to his people. Ezekiel is told to eat bread made of mingled seeds and baked over the dung of people and cattle. He is commanded to experience the death of his wife without shedding a tear. Amos is driven from Samaria. Why is he driven from it? Surely in this case, as in the others, because he was a spiritual surgeon who cut away the parts diseased by sin and urged people to repentance. The apostle Paul says, "Am I therefore become your enemy because I tell you the truth?" And so the Savior found it, from whom many of the disciples turned back from following him because his sayings seemed hard.