Sayyiduna al-Mughirah bin Shu'bah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) ate some food, then the prayer was established, and he (peace and blessings be upon him) stood up; he had already performed ablution before that. I brought him water so that he might perform ablution with it, but he rebuked me and said: Get back! (The narrator says:) By Allah, this weighed heavily on me. Then he (peace and blessings be upon him) prayed. I complained about this to Sayyiduna Umar (may Allah be pleased with him), and he said: O Prophet of Allah, your rebuke of al-Mughirah has weighed heavily on him, and he fears that you may be displeased with him. The Prophet (peace and blessings be upon him) said: There is nothing but good in my heart (towards him). He brought me water so that I might perform ablution, but I had only eaten food. Had I done so, the people after me would have done the same.
Imam Ahmad and Imam al-Tabarani (in al-Mu'jam al-Kabir) recorded this report, and its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطهارة / 1315