Abdullah bin Abbas reported,

Umar used to include me in the gatherings of the elders of Badr. It seemed that some of them felt uneasy about this, and one of them said, "Why do you bring this boy in with us when we have sons his age?"Umar replied, "He is the one whose status you already know."Then one day Umar called me and brought me into their gathering, and I felt that he had only summoned me that day to display me to them.He asked, "What do you say about the words of Allah Most High, 'When the help of Allah comes and the victory'?"Some of them said, "We are commanded to praise Allah and seek His forgiveness when He grants us help and victory."Others remained silent and said nothing.Then Umar said to me, "Is that what you say too, Ibn Abbas?"I said, "No."He said, "Then what do you say?"I replied, "It refers to the appointed term of the Messenger of Allah ﷺ, which Allah was making known to him. He said, 'When the help of Allah comes and the victory', and that is the sign of your appointed term, 'so glorify the praise of your Lord and seek His forgiveness. Indeed, He is ever Accepting of repentance' [Nasr 110:1–3]."Umar said, "I know nothing of it except what you have said."

Bukhari 4970

Sahih

حدثنا موسى بن إسماعيل حدثنا أبو عوانة عن أبي بشر عن سعيد بن جبير

عن ابن عباس قال

كان عمر يدخلني مع أشياخ بدر فكأن بعضهم وجد في نفسه فقال لم تدخل هذا معنا ولنا أبناء مثله فقال عمر إنه من قد علمتم فدعاه ذات يوم فأدخله معهم فما رئيت أنه دعاني يومئذ إلا ليريهم قال ما تقولون في قول الله تعالى إذا جاء نصر الله والفتح فقال بعضهم أمرنا أن نحمد الله ونستغفره إذا نصرنا وفتح علينا وسكت بعضهم فلم يقل شيئا فقال لي أكذاك تقول يا ابن عباس فقلت لا قال فما تقول قلت هو أجل رسول الله ﷺ أعلمه له قال إذا جاء نصر الله والفتح وذلك علامة أجلك {فسبح بحمد ربك واستغفره إنه كان توابا} فقال عمر ما أعلم منها إلا ما تقول

البخاري 4970صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Tafsir
Chapter
So exalt with praise of your Lord and ask forgiveness of Him. Indeed, He is ever accepting of repentance
Numbering
Darussalam 4970
Bukhari 4970