Musnad Ahmad 25:1494

Waki' narrated to us, from Sufyan, from 'Asim, from Abu Razin, that 'Umar asked Ibn 'Abbas about this verse: {When the victory of Allah has come and the conquest} [An-Nasr: 1]. He said: "When it was revealed, the Prophet, may Allah bless him and grant him peace, was informed of his own death."