وَمِنْهُم مَّنْ عَاهَدَ اللَّهَ لَئِنْ آتَانَا مِن فَضْلِهِ لَنَصَّدَّقَنَّ وَلَنَكُونَنَّ مِنَ الصَّالِحِينَ
“And there are some who had made a vow to Allah: "If He gives us from His bounty, we will surely spend in charity and be of the righteous."”
This ayah is part of Surat al-Tawba's Tabuk-era passage addressing the hypocrites and excuse-makers who stayed behind or mocked the campaign, described at this event.