Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Bukhari :: Book 5 :: Volume 59 :: Hadith 555
Narrated Mujahid:
'Urwa and I entered the Mosque and found 'Abdullah bin 'Umar sitting beside the dwelling place of 'Aisha. 'Urwa asked (Ibn 'Umar), "How many 'Umras did the Prophet perform?" Ibn 'Umar replied, "Four, one of which was in Rajab." Then we heard 'Aisha brushing her teeth whereupon 'Urwa said, "O mother of the believers! Don't you hear what Abu 'Abdur-Rahman is saying? He is saying that the Prophet performed four 'Umra, one of which was in Rajab." 'Aisha said, "The Prophet did not perform any 'Umra but he (i.e. Ibn 'Umar) witnessed it. And he (the Prophet ) never did any 'Umra in (the month of) Rajab."