Ibn 'Asakir reported on the authority of Jalhamah bin 'Arfuta who said: "I came to Makkah when it was a rainless year, so Quraish said 'O Abu Talib, the valley has become leafless and the children hungry, let us go and pray for rain-fall.' Abu Talib went to Al-Ka'bah with a young boy who was as beautiful as the sun, and a black cloud was over his head. Abu Talib and the boy stood by the wall of Al-Ka'bah and prayed for rain. Immediately clouds from all directions gathered and rain fell heavily and caused the flow of springs and growth of plants in the town and the country.
Source: Mukhtasar Seeratir-Rasul by Sheikh Abdullah An-Najdi.