If anyone says Amin [during the Salat (prayer) at the end of the recitation of Surat Al-Fatiha]
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ إِسْمَاعِيلَ، حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ الأَنْصَارِيُّ، عَنِ ابْنِ عَوْنٍ، أَنْبَأَنَا الْقَاسِمُ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ مَنْ زَعَمَ أَنَّ مُحَمَّدًا رَأَى رَبَّهُ فَقَدْ أَعْظَمَ، وَلَكِنْ قَدْ رَأَى جِبْرِيلَ فِي صُورَتِهِ، وَخَلْقُهُ سَادٌّ مَا بَيْنَ الأُفُقِ.
Narrated Aisha: Whoever claimed that (the Prophet) Muhammad saw his Lord, is committing a great fault, for he only saw Gabriel in his genuine shape in which he was created covering the whole horizon.