The answer is: Camel's hair

Matt 3:4 - A rough and coarse garment like the prophets used to wear. c.f. Zec 13:4; 2 Ki 1:8

John the Baptist's fashion choice—pretty unconventional by today’s standards—was quite telling and connected deeply to prophetic traditions. Dressed in camel's hair, he was dressing for more than just comfort; he was announcing a message through his attire. In the context of Jewish tradition, camel hair garments symbolized simplicity and humility, which helped to communicate his radical message of repentance.

Did you know that wearing garments made from animal hair in the ancient world was not solely about fashion? Prophets like Elijah wore similar attire (2 Kings 1:8), emphasizing their role as messengers from God. The bard of the desert, John wasn’t shy to wear a label considered scruffy and rough, contrasting sharply with the luxuries of Herod’s court, where he'd later find himself in a *real* sticky situation.

Additionally, his choice taps into Zachariah’s prophecy (Zechariah 13:4) where false prophets would don hairy mantles to feign authenticity. John’s wardrobe, thus, set him apart as a true authenticator of the Messianic line. And talk about a character—while today many may think camel hair sounds chic unstuffed with meaning, back then it reflected radical sincerity—a much-needed quality in spiritual leaders still today!

So the next time you think of John's rugged sartorial style, remember he was setting the stage for much, much more than just a cool appearance. His dress was an echo through the ages, wrapping around prophetic tradition and presenting a lived persona ready for the voice of one calling in the wilderness!