´Jabir bin Abdullah narrated:` "When the Prophet wanted to Perform Hajj, he announced it to the people, and they gathered (to accompany him). When he reached Al-Baida he assumed Ihram"
Hadith ReferenceSunan at-Tirmidhi / The Book on Hajj / Hadith: 817
Hadith Gradingالألبانی:صحيح حجة النبى صلى الله عليه وسلم (45 / 2)