Musnad Ahmad 3:24

'Abd al-Razzaq narrated to us, Ma'mar informed us, from Ayyub, from Nafi', from Nabih ibn Wahb, who said: 'Umar ibn 'Ubayd Allah sent [a message] to Aban ibn 'Uthman: "May he apply kohl to his eyes while he is in the state of ihram? Or with what thing should he apply kohl to them while he is in the state of ihram?" He sent back to him: "That he should dress them with aloe (sabir), for I heard 'Uthman ibn 'Affan narrating that from the Messenger of Allah, may Allah bless him and grant him peace."