Sahih al-Bukhari 1008, 1009

Narrated `Abdullah bin Dinar: My father said, "I heard Ibn `Umar reciting the poetic verses of Abu Talib: And a white (person) (i.e. the Prophet) who is requested to pray for rain and who takes care of the orphans and is the guardian of widows." Salim's father (Ibn `Umar) said, "The following poetic verse occurred to my mind while I was looking at the face of the Prophet (ﷺ) while he was praying for rain. He did not get down till the rain water flowed profusely from every roof-gutter: And a white (person) who is requested to pray for rain and who takes care of the orphans and is the guardian of widows . . . And these were the words of Abu Talib."