يَعْتَذِرُونَ إِلَيْكُمْ إِذَا رَجَعْتُمْ إِلَيْهِمْ ۚ قُل لَّا تَعْتَذِرُوا لَن نُّؤْمِنَ لَكُمْ قَدْ نَبَّأَنَا اللَّهُ مِنْ أَخْبَارِكُمْ ۚ وَسَيَرَى اللَّهُ عَمَلَكُمْ وَرَسُولُهُ ثُمَّ تُرَدُّونَ إِلَىٰ عَالِمِ الْغَيْبِ وَالشَّهَادَةِ فَيُنَبِّئُكُم بِمَا كُنتُمْ تَعْمَلُونَ
“They will make excuses to you [believers] when you return to them. Say, "Make no excuses, [for] we will not believe you. Allah has already informed us about your [true] state [of faith]. Your [future] deeds will be observed by Allah and His Messenger as well. And you will be returned to the Knower of the seen and unseen, then He will inform you of what you used to do."”
This ayah is part of the Qur'an's direct response to the excuse-making scene the post narrates, upon the army's return from Tabuk.