Musnad Ahmad 27:1567

Abu al-Yaman narrated to us, Shu'ayb informed us, from al-Zuhri, Salim ibn 'Abd Allah informed me, from 'Abd Allah ibn 'Umar, who said: I heard 'Umar saying: "Whoever braids [his hair], let him shave it, and do not resemble [the practice of] *talbid* (matted hair)." And Ibn 'Umar used to say: "I have indeed seen the Messenger of Allah, may Allah bless him and grant him peace, with matted hair (*mulabbidan*)."