Sackcloth: Made of Coarse Hair
Source: TTT
Matthew 3:4
John wore a garment of camel’s hair, with a leather belt around his waist. His food was locusts and wild honey.
Revelation 6:12
And when I saw the Lamb open the sixth seal, there was a great earthquake, and the sun became black like sackcloth of goat hair, and the whole moon turned blood red,