as a man sows, so shall he reap

as a man sows, so shall he reap

A person's actions dictate the consequences they encounter. The phrase is Biblical in origin. Of course you're exhausted in class—you stay up too late! As a man sows, so shall he reap. He spent years trying to avoid paying taxes, and now he's facing nearly 10 years in prison for it. As a man sows, so shall he reap.
See also: he, man, reap, shall