Musnad Abu Ya'la al-Mawsili 160:15

Abu Khaythama narrated to us, Jarir narrated to us, from Layth, from Ka'b, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "You will be the bright-faced and bright-limbed ones on the Day of Resurrection because of the traces of ablution. So whoever among you is able to lengthen his brightness, let him do so."