Sahih Bukhari
Shortening the Prayers (At-Taqseer)
Volume: 002 / Book Number: 020 / Hadith Number: 191
Narrated Ibn Abbas:
The Prophet and his companions reached Mecca in the morning of the 4th Dhul-Hijja reciting Talbiya (O Allah! We are obedient to your orders, we respond 4 to your call) . . . intending to perform Hajj. The Prophet ordered his companions to assume the lhram for Umra instead of Hajj, excepting those who had Hadi (sacrifice) with them.