Humayd bin Hilal narrates: Sayyiduna Abu Rifa'ah (may Allah be pleased with him) used to heat water for his companions and would then say: Perform ablution well with this; I shall perform it even better than this. (The narrator says:) And then he himself would perform ablution with cold water.
Imam al-Tabarani recorded this narration in al-Mu'jam al-Kabir, and its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطهارة / 1074