Washing the Limbs Thoroughly in Wudhu

وعن عبد الله بن عمرو رضي الله عنهما أن رسول الله صلى الله عليه وسلم رأى قوما وأعقابهم تلوح فقال ويل للأعقاب من النار أسبغوا الوضوء رواه مسلم وأبو داود واللفظ له والنسائي وابن ماجه ورواه البخاري بنحوه (الترغيب والترهيب 1/235)

Hazrat Abdullah bin Amr (radhiyallahu ‘anhu) reports that Rasulullah (sallallahu ‘alaihi wasallam) once saw some people whose heels were shining (due to them not washing their heels at the time of performing wudhu). Rasulullah (sallallahu ‘alaihi wasallam) said: “Doom and destruction in the fire of Jahannum is for those (who during wudhu do not wash their) heels. Carry out a perfect wudhu.”