Mukhtasar Bukhari

Narrated from Sayyiduna Umar bin Khattab (may Allah be pleased with him) that when people were afflicted by drought, the Commander of the Faithful, Umar bin Khattab (may Allah be pleased with him), would ask for rain through Sayyiduna Abbas bin Abdul Muttalib (may Allah be pleased with him). He would say: O Allah! (Previously) we used to supplicate to You for rain through our Noble Prophet (peace and blessings of Allah be upon him) and You would send down rain. Now we supplicate to You through the uncle of our Noble Prophet (peace and blessings of Allah be upon him), so (now also) send down rain. (Sayyiduna Anas, may Allah be pleased with him, says that) it would start to rain.