Sahih Bukhari Volume 005, Book 059, Hadith Number 707.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 59. Military Expeditions Led by the Prophet (PBUH) (Al-Maghaazi)
Narrated By Anas bin Malik : Allah's Apostle returned from the Ghazwa of Tabuk, and when he approached Medina, he said, "There are some people in Medina who were with you all the time, you did not travel any portion of the journey nor crossed any valley, but they were with you they (i.e. the people) said, "O Allah's Apostle! Even though they were at Medina?" He said, "Yes, because they were stopped by a genuine excuse."