Man must be sharpened on man, like knife on stone

Similar sayings:

The pen can kill a man; no knife is needed The pen can kill a man; no knife is needed
The man who removes a mountain begins by carrying away small stones The man who removes a mountain begins by carrying away small stones
A jade stone is useless before it is processed; a man is good-for-nothing until he is educated A jade stone is useless before it is processed; a man is good-for-nothing until he is educated
Don’t waste too many stones on one bird Don’t waste too many stones on one bird
To persecute the unfortunate is like throwing stones on one fallen into a well To persecute the unfortunate is like throwing stones on one fallen into a well

Chinese sayings and proverbs