Majma al-Zawaid — Hadith 3287

Umar bin Kharijah bin Sa'd narrated from his grandfather, Sayyiduna Sa'd (may Allah be pleased with him): Some people complained to the Prophet (peace and blessings be upon him) about the lack of rain. The Prophet (peace and blessings be upon him) ordered them to get down on their knees, so they got down on their knees. Then the Prophet (peace and blessings be upon him) said: "Say: 'O our Lord!'" They did so, and rain began to fall upon them (and it continued for so long) that they wished: "If only this rain would stop." These are the words of the narration as recorded by al-Bazzar. Al-Tabarani recorded it in al-Mu'jam al-Awsat: Amir bin Kharijah bin Sa'd narrated from his father, from his grandfather, Sayyiduna Sa'd (may Allah be pleased with him): "Some people complained to the Prophet (peace and blessings be upon him) about the lack of rain, and he (peace and blessings be upon him) said: 'Get down on your knees and say: O our Lord! O our Lord!' Then the Prophet (peace and blessings be upon him) raised his index finger toward the sky, and rain began to fall upon the people (and it continued for so long) that the people wished: 'Now let this rain stop.'"
The narration recorded by al-Tabarani is the correct one. He gave the name as Amir, and that is how it is: al-Dhahabi mentioned this man in the same way in the biography of Amir bin Kharijah, and declared him da'if (weak).