Wearing camel's hair and a leather belt had a specific spiritual meaning.
When we first meet John the Baptist in the Gospels of Matthew and Mark, he is an odd character. The Gospel writers go out of their way to describe his unusual clothing, in one of the rare occasions that they ever mention someone’s garments.
Now John wore a garment of camel’s hair, and a leather girdle around his waist; and his food was locusts and wild honey. (Matthew 3:4)
Besides showing John’s poverty, what does his clothing signify?
For a Jewish audience, this detail linked John the Baptist to a very significant prophet in the Old Testament. The prophet Elijah wore similar clothing that set him apart from everyone else.
They answered him, “He wore a garment of haircloth, with a girdle of leather about his loins.” And he said, “It is Elijah the Tishbite.” (2 Kings 1:8)
In the book of Malachi, it was foretold that, “Behold, I will send you Elijah the prophet before the great and terrible day of the Lord comes. And he will turn the hearts of fathers to their children and the hearts of children to their fathers, lest I come and smite the land with a curse” (Malachi 4:5).
Even Jesus made the connection, further solidifying the role of John the Baptist as a prophet who would prepare the way for the Messiah, “Truly, I say to you, among those born of women there has risen no one greater than John the Baptist … and if you are willing to accept it, he is Elijah who is to come” (Matthew 11:11,14).
Additionally, Jesus contrasts the mission of John the Baptist with the “soft” garments of royalty.
As they went away, Jesus began to speak to the crowds concerning John: “What did you go out into the wilderness to behold? A reed shaken by the wind? Why then did you go out? To see a man clothed in soft raiment? Behold, those who wear soft raiment are in kings’ houses. Why then did you go out? To see a prophet? Yes, I tell you, and more than a prophet.” (Matthew 11:7,9)
Last of all the coarse garments of John the Baptist symbolize his mission to preach repentance. Sackcloth is a similar garment referred to in the Old Testament and frequently was worm when in mourning or in a public show of repentance for sin.
While his clothing choices may seem odd to the modern reader, they made perfect sense to the 1st-century Jewish follower, who instantly understand the significance of his garments.