Easton's Bible Dictionary: M. G. Easton, M.A., D.D.
One of the particulars regarding which retaliatory punishment was to be inflicted (Ex. 21:24; Lev. 24:20; Dt. 19:21). "Gnashing of teeth" =rage, despair (Mt. 8:12; Acts 7:54); "cleanness of teeth" =famine (Amos 4:6); "children's teeth set on edge" =children suffering for the sins of their fathers (Ezek. 18:2).