Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Bukhari :: Book 5 :: Volume 59 :: Hadith 740
Narrated 'Aisha:
When the Prophet was healthy, he used to say, "No soul of a prophet is captured till he is shown his place in Paradise and then he is given the option." When death approached him while his head was on my thigh, he became unconscious and then recovered his consciousness. He then looked at the ceiling of the house and said, "O Allah! (with) the highest companions." I said (to myself), "Hence, he is not going to choose us." Then I realized that what he had said was the application of the narration which he used to mention to us when he was healthy. The last word he spoke was, "O Allah! (with) the highest companion."