If anyone says Amin [during the Salat (prayer) at the end of the recitation of Surat Al-Fatiha]
حَدَّثَنَا حَفْصُ بْنُ عُمَرَ، حَدَّثَنَا شُعْبَةُ، عَنِ الأَعْمَشِ، عَنْ إِبْرَاهِيمَ، عَنْ عَلْقَمَةَ، عَنْ عَبْدِ اللَّهِ ـ رضى الله عنه – {لَقَدْ رَأَى مِنْ آيَاتِ رَبِّهِ الْكُبْرَى} قَالَ رَأَى رَفْرَفًا أَخْضَرَ سَدَّ أُفُقَ السَّمَاءِ.
Narrated `Abdullah: Regarding the Verse: "Indeed he (Muhammad) did see. Of the Signs of his Lord, The Greatest!" (53.18) That the Prophet (ﷺ) had seen a green carpet spread all over the horizon of the sky.