Quran 9:43 At-Tawbah, ayah 43 of 129

عَفَا ٱللَّهُ عَنكَ لِمَ أَذِنتَ لَهُمْ حَتَّىٰ يَتَبَيَّنَ لَكَ ٱلَّذِينَ صَدَقُوا۟ وَتَعْلَمَ ٱلْكَـٰذِبِينَ ۝٤٣

9:43 Allah forgive thee (O Muhammad)! Wherefor didst thou grant them leave ere those who told the truth were manifest to thee and thou didst know the liars?