Harm watch, harm catch.
Used to suggest that those who intentionally seek to harm others are likely to attract harm to themselves as well. Those who are promoters of harmful thoughts, ideas and actions, will, at some later time, be the recipient of similar thoughts, ideas and actions.
i.e. You reap what you sow
John Donne, an English poet, wrote secular poems as well as erotic and love poems. He is particularly famous for his mastery of metaphysical conceits.
In his book titled: Donne's satyr *
He included this peom:
Of Harm watch, harm catch.