Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "A man was passing through a wilderness when suddenly he heard the sound of thunder from the clouds, and he also heard some words: 'Water the garden of so-and-so,' and his name was mentioned. Then that cloud came to a plain and poured out all the water it held there, and that water gathered towards a channel in the valley and began to flow like a stream. The man walked along with the clouds until he came to a man standing in his garden, watering it. He said: 'O servant of Allah, what is your name?' He said: 'Why do you ask?' He said: 'I heard from this cloud: "Water the garden of so-and-so," said with your name. So when you harvest it, what do you do with it?' He said: 'Since you ask, I will tell you: I divide it into three parts. I keep one part for myself and my family, I put one part back into it, and I distribute one part among the poor, the needy and the travellers.'"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7512