Mukhtasar Bukhari

It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that in the beginning, the Messenger of Allah (peace and blessings be upon him) would let the hair of his forelock hang forward, while the polytheists would part their hair. The People of the Book would let their hair hang, and the Messenger of Allah (peace and blessings be upon him), in matters where no command had come, preferred to agree with the People of the Book rather than the polytheists. Then after that, the Prophet (peace and blessings be upon him) began to part his hair.