John Wesley on Lamentations 4:14

They - The prophets and priests wandered up and down the streets polluting themselves with blood, either the blood of the children which they slew, or the just men, mentioned ver.13, the slaughter of whom they either encouraged, or at least did not discourage; so that one could not touch a prophet or priest, but he must be legally polluted, and there were so many of them, that men could not walk in the streets, but he must touch some of them.