While a person was in the wilderness, he heard a voice from the cloud (commanding it thus): Irrigate the garden of so and so. After that the clouds slinked aside and poured water on a stony ground.It filled a channel amongst the channels of that land and that person followed that water and he found a person standing in the garden busy in changing the course of water with the help of a hatchet.

He said to him: Servant of Allah, what is your name?

he said: So and so.

And it was that very name which he had heard from the clouds.

And he said to him: Servant of Allah, why do you ask me my name?

He said: I heard a voice from the clouds of which It is the downpour, saying: Water the garden of so and so, like your name. What do you do (for the favour) shown to you by Allah in this matter?

He said: Now as you state so, I look what yield I get from it, and I give one-third as charity out of it,  I and my children eat one-third of it and one-third I return to it as investment.

Based on Sahih MUslim, Book 42, Number 7112