Abdullah bin Abbas reported,

Umar bin Khattab used to bring Ibn Abbas close to him, so Abd al-Rahman bin Awf said to him, "We have sons like him."Umar replied, "He is from where you know."Then Umar asked Ibn Abbas about this verse, "When the help of Allah comes and the victory" [Nasr 110:1].Ibn Abbas said, "It is the appointed term of the Messenger of Allah ﷺ, which Allah informed him of."Umar said, "I know nothing of it except what you know."

Azami 9312

Sahih

عن ابن عباس

قال كان عمر بن الخطاب يدني ابن عباس، فقال له عبد الرحمن بن عوف: إن لنا أبناء مثله فقال: إنه من حيث تعلم، فسأل عمر ابن عباس عن هذه الآية {إذا جاء نصر الله والفتح} فقال: أجل رسول الله ﷺ أعلمه إياه. قال: ما أعلم منها إلا ما أعلم منها إلا ماتعلم.

الأعظمي 9312صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Biography of the Prophet ﷺ
Chapter
Nearness of his death, his foretelling of it, his passing, and his burial
Section
Revelation of Surah Nasr and the indication therein of the nearness of his death
Numbering
Jami al-Kamil 9312 (2nd edition)
Azami 9312