If you put a razor in your mouth, you will spit blood.
More Nigerian Proverbs:
Don't look for speed in a cheap horse; be content if it neighs.Nigerian
The hunter does not rub himself in oil and lie by the fire to sleep.
Nigerian
When the mice laugh at the cat, there is a hole nearby.
Nigerian
That which brings misfortune is not big.
Nigerian
The well gives, but the bucket refuses.
Nigerian
The one-eyed man thanks God only when he sees a man blind in both eyes.
Nigerian