If anyone says Amin [during the Salat (prayer) at the end of the recitation of Surat Al-Fatiha]
حَدَّثَنَا يَحْيَى بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنِي ابْنُ وَهْبٍ، قَالَ حَدَّثَنِي عُمَرُ، عَنْ سَالِمٍ، عَنْ أَبِيهِ، قَالَ وَعَدَ النَّبِيَّ صلى الله عليه وسلم جِبْرِيلُ فَقَالَ إِنَّا لاَ نَدْخُلُ بَيْتًا فِيهِ صُورَةٌ وَلاَ كَلْبٌ.
Narrated Salim's father: Once Gabriel promised the Prophet (that he would visit him, but Gabriel did not come) and later on he said, "We, angels, do not enter a house which contains a picture or a dog."