The Prophet ﷺ saw a group of people performing ablution who did not complete it properly, so he said, "Woe to the heels from the Fire."
حدثنا محمد بن جعفر حدثنا شعبة عن أبي بشر عن رجل من أهل مكة
عن النبي ﷺ أنه رأى قوما توضئوا لم يتموا الوضوء فقال ويل للأعقاب من النار
Its isnad is sahih, despite the apparent ambiguity regarding the identity of the follower who narrated it. Abu Bishr is Jafar bin Iyas, who is Ibn Abu Wahshiya, al-Yashkuri, whose biography was given previously at 6259. The man from the people of Makkah, from whom Abu Bishr narrated it, is Yusuf bin Mahak, as indicated by the two forthcoming narrations 6976 and 7103, and as the Hafiz stated explicitly in al-Tajil, p. 551. Ibn Mahak's biography was given previously at 6510. The hadith appears abridged at 6883 and in full at 6528, and we have already noted this there.