Ofu mkpụrụ aka rụta mmanụ, ya ezụọ ibe ya.

Literal translation

If one finger touches oil, it spreads to the others.

Explanation

Oil moves from one finger to its neighbours. The image describes how a consequence can spread through a group.

When to use it

When a decision made by one person has effects on others.

Source: Anyabuike, proverb 15.