Sahih Bukhari Volume 6, Book 60, Hadith Number 493.

Narrated By Ibn Abbas : ‘Umar asked the people regarding Allah’s Statement:

‘When comes the Help of Allah (to you O Muhammad against your enemies) and the conquest of Mecca.’ (110.1) They replied, “It indicates the future conquest of towns and palaces (by Muslims).” ‘Umar said, “What do you say about it, O Ibn ‘Abbas?” I replied, “(This Surat) indicates the termination of the life of Muhammad. Through it he was informed of the nearness of his death.”