Caves were Used as Haunts of Robbers
Source: TTT
Jeremiah 7:11
Has this house, which bears My Name, become a den of robbers in your sight? Yes, I too have seen it, declares the LORD.
Matthew 21:13
And He declared to them, “It is written: ‘My house will be called a house of prayer.’ But you are making it ‘a den of robbers.’”