It was narrated from ‘Abdul-Jabbar bin Wa’il that his father said:
“I performed prayer with the Prophet ﷺ and when he said: ‘Nor of those who went astray’,[1:7] he said Amin and we heard that from him.”

حَدَّثَنَا مُحَمَّدُ بْنُ الصَّبَّاحِ، وَعَمَّارُ بْنُ خَالِدٍ الْوَاسِطِيُّ، قَالاَ حَدَّثَنَا أَبُو بَكْرِ بْنُ عَيَّاشٍ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَبْدِ الْجَبَّارِ بْنِ وَائِلٍ، عَنْ أَبِيهِ، قَالَ صَلَّيْتُ مَعَ النَّبِيِّ ﷺ فَلَمَّا قَالَ {وَلاَ الضَّالِّينَ} . قَالَ " آمِينَ " . فَسَمِعْنَاهَا مِنْهُ .