Psalm 64:8 in the World English Bible
Their own tongues shall ruin them. All who see them will shake their heads.
Context
7 But God shall shoot at them with an arrow; suddenly shall they be wounded.
8 So they shall make their own tongue to fall upon themselves: all that see them shall flee away.
9 And all men shall fear, and shall declare the work of God; for they shall wisely consider of his doing.