Sahih Bukhari
Fighting for the Cause of Allah (Jihaad)
Volume: 004 / Book Number: 052 / Hadith Number: 218
Narrated Tha'laba bin Abi Malik Al-Qurazi:
When Qais bin Sad Al-Ansari, who used to carry the flag of the Prophet, intended to perform Hajj, he combed his hair.