You Reap What You Sow refers to the same universal concept as “karma”.
It means that whatever you put into the world, be it kindness, love, excitement, sadness, evil, negativity – it will come back to you.
The concept can be understood both in a spiritual sense, that your positive/negative energy will come back to you someday, or simply just in a logical sense:
If you are being a dick to everyone around you, they will be a dick to you too.
You tell someone “you reap what you sow” when something completely expected happens based on their previous actions.
“You reap what you sow” is a metaphor that has been so much used it became a proverb.
“To reap” means to gather your crops, while to sow equals to plant them.
Hence, naturally, what you produce is what you get.
A similar quote was mentioned in the Old Testament of the Bible, when the Israelites started worshipping a gold calf. God responds by saying: “They sow the wind, and reap the whirlwind.”
Then he punished them.
The quote has repeatedly been mentioned in various shapes in religious texts, particularly biblical writings.
We see it several times in King James Bible from 1611, and also in the New Testament.
In 1965, Martin Luther King Jr. finished his famous speech by using the proverb.
The alternative rock band Rage against the Machine included the proverb in their lyrics for the track “Wake Up”.
The term may also be used in everyday speech, for example if your rude and lazy coworker finally got fired.