What were the words of the Prophet Muhammad (saw) when he noticed some of his companions merely passing wet hands over their feet rather than performing ablution properly for `Asr prayer?
 Narrated `Abdullah bin `Amr:                     Once Allah's Apostle remained behind us in a journey. He joined us while we were performing ablution for the `Asr prayer which was over-due. We were just passing wet hands over our feet (not washing them properly) so the Prophet addressed us in a loud voice and said twice or thrice, "Save your heels from the fire."