Sahih Bukhari Volume 5, Book 59, Hadith Number 713.
Narrated By Ibn Abbas : ‘Umar bin Al-Khattab used to let Ibn Abbas sit beside him, so ‘AbdurRahman bin ‘Auf said to ‘Umar, “We have sons similar to him.” ‘Umar replied, “(I respect him) because of his status that you know.” ‘Umar then asked Ibn ‘Abbas about the meaning of this Holy Verse: “When comes the help of Allah and the conquest of Mecca…” (110.1)
Ibn ‘Abbas replied, “That indicated the death of Allah’s Apostle which Allah informed him of.” ‘Umar said, “I do not understand of it except what you understand.”
Narrated ‘Aisha: The Prophet in his ailment in which he died, used to say, “O ‘Aisha! I still feel the pain caused by the food I ate at Khaibar, and at this time, I feel as if my aorta is being cut from that poison.”