It was narrated that Abu Dharr said:The messenger of Allah(ﷺ) said: "When anyone of you stands to pray, then he is screened if he has in front of him something as high as the back of a camel saddle. If he does not have something as high as the back of a camel saddle in front of him, then his prayer is nullified by a woman, a donkey or a black dog." I (one of the narrators)said: "What is the difference between a black dog, a yellow one and a red one?" He said: I asked the Messenger of Allah (ﷺ) just like you and he said:"The black dog is a shaitan."
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ أَنْبَأَنَا يَزِيدُ، قَالَ حَدَّثَنَا يُونُسُ، عَنْ حُمَيْدِ بْنِ هِلاَلٍ، عَنْ عَبْدِ اللَّهِ بْنِ الصَّامِتِ، عَنْ أَبِي ذَرٍّ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا كَانَ أَحَدُكُمْ قَائِمًا يُصَلِّي فَإِنَّهُ يَسْتُرُهُ إِذَا كَانَ بَيْنَ يَدَيْهِ مِثْلُ آخِرَةِ الرَّحْلِ فَإِنْ لَمْ يَكُنْ بَيْنَ يَدَيْهِ مِثْلُ آخِرَةِ الرَّحْلِ فَإِنَّهُ يَقْطَعُ صَلاَتَهُ الْمَرْأَةُ وَالْحِمَارُ وَالْكَلْبُ الأَسْوَدُ " . قُلْتُ مَا بَالُ الأَسْوَدِ مِنَ الأَصْفَرِ مِنَ الأَحْمَرِ فَقَالَ سَأَلْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم كَمَا سَأَلْتَنِي فَقَالَ " الْكَلْبُ الأَسْوَدُ شَيْطَانٌ " .
Nesai
The Book of the Qiblah • Hadith 750