what goes around comes around

"What goes around comes around" means that if a person does something bad, sooner or later something bad will happen to that person; and if you treat people well, something good will happen to you. The idea is that a person will receive what they deserve based on their actions towards another.(Grayson) — что посеешь, то и пожнешь; как аукнется, так и откликнется

see also
[as you sow, so shall you reap]
[отольются кошке мышкины слёзки]
[не рой другому яму]