"And their saying was not" when they met their enemy "except that they said: Our Lord, forgive us our sins and our excesses in our affairs," meaning: their faults.
﴿وَمَا كَانَ قَوْلهم﴾ حِين لقوا عدوهم ﴿إِلا أَنْ قَالُوا رَبَّنَا اغْفِرْ لَنَا ذُنُوبَنَا وإسرافنا فِي أمرنَا﴾ يُرِيدُونَ: خطاياهم.