Cast off their clothes - Their outer garments. Probably they did it now intending to stone him, Acts 7:58.
And threw dust into the air - As expressive of them abhorrence and indignation. This was a striking exhibition of rage and malice. Paul was guarded by Roman soldiers so that they could not injure him; and their only way of expressing their wrath was by menaces and threats, and by these tokens of furious indignation. Thus, Shimei expressed his indignation against David by cursing him, throwing stones at him, and casting dust, 2 Samuel 16:13.