Dhammapada verses 124 and 125

124. If on the hand there is no wound, one may carry even poison in it. Poison does not affect one who is free from wounds. For him who does no evil, there is no ill.

125. Like fine dust thrown against the wind, evil falls back upon that fool who offends an inoffensive, pure and guiltless man.

– Dhammapada IX – Papavagga: Evil 124 and 125