Narrated Marwan and Al-Miswar bin Makhrama: The Prophet went out in the company of 1300 to 1500 of his companions in the year of Al-Hudaibiya, and when they reached Dhul-Hulaifa, he garlanded and marked his Hadi and assumed the state of Ihram.
— Sahih Bukhari, Volume 5, Book 59: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi), Hadith #477