Musnad Abu Ya'la al-Mawsili 110:277

Narrated to us Zuhayr, narrated to us Abdullah bin Ja'far al-Raqqi, narrated to us Ubaydullah—meaning Ibn Amr—from Abd al-Karim, from Sa'id bin Jubayr, from Ibn Abbas, that the Prophet (peace and blessings of Allah be upon him) said: "There will be a people who will dye [their hair/beards] with black at the end of time, like the crops of pigeons; they will not smell the fragrance of Paradise."