What he did once it was all over
After the conquest, and after the sūrah that announced it.
سُبْحَانَكَ رَبَّنَا وَبِحَمْدِكَ، اللَّهُمَّ اغْفِرْ لِي
Subḥānaka rabbanā wa bi-ḥamdik, Allāhumma-ghfir lī.
“Glory be to You, our Lord, and praise. O Allah, forgive me.”
Aisha said he did not pray a prayer after it without saying this.
The full narration
Narrated Aisha:"When the "Surat-An-Nasr", 'When comes the Help of Allah and the conquest,' had been revealed to the Prophet (ﷺ) he did not offer any prayer except that he said therein, "Subhanka Rabbana wa bihamdika; Allahumma ighfirli (I testify the Uniqueness of our Lord, and all the praises are for Him: O Allah, forgive me)
Source
Ṣaḥīḥ al-Bukhārī · 4967
Ṣaḥīḥ
- Agreed upon as authentic (al-Bukhārī / Muslim)