Narrated `Abdullah bin `Amr: The Prophet remained behind us on a journey. He joined us while we were performing ablution for the `Asr prayer which was overdue and we were just passing wet hands over our feet (not washing them thoroughly) so he addressed us in a loud voice saying twice , "Save your heels from the fire."
Hadith Referenceصحيح البخاري / كتاب الوضوء / 163
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة