Sahih Bukhari Volume 7, Book 72, Hadith Number 796.

Narrated By ‘Abdullah bin ‘Umar  : I heard ‘Umar saying, “Whoever braids his hair should shave it (on finishing lhram). You’d better not do, something like Talbid.” Ibn Umar used to say: “I saw Allah’s Apostle with his hair stuck together with gum.”