Messenger of Allah said: "When a man performs Salat, and there is nothing in front of him like the post of a saddle, or a camel saddle, then his Salat is severed by (passing of) a black dog, a woman, and a donkey." It was said to Abu Dharr: "What is the problem with the black dog rather than the red or white one?" He said: "O my nephew! I asked Messenger of Allah just as you have asked me. He said: 'The black dog is a Shaitan (devil).'"  

قَالَ رَسُولُ اللَّهِ ﷺ إِذَا صَلَّى الرَّجُلُ وَلَيْسَ بَيْنَ يَدَيْهِ كَآخِرَةِ الرَّحْلِ أَوْ كَوَاسِطَةِ الرَّحْلِ قَطَعَ صَلاَتَهُ الْكَلْبُ الأَسْوَدُ وَالْمَرْأَةُ وَالْحِمَارُ فَقُلْتُ لأَبِي ذَرٍّ مَا بَالُ الأَسْوَدِ مِنَ الأَحْمَرِ مِنَ الأَبْيَضِ فَقَالَ يَا ابْنَ أَخِي سَأَلْتَنِي كَمَا سَأَلْتُ رَسُولَ اللَّهِ ﷺ فَقَالَ الْكَلْبُ الأَسْوَدُ شَيْطَانٌ قَالَ وَفِي الْبَابِ عَنْ أَبِي سَعِيدٍ وَالْحَكَمِ بْنِ عَمْرٍو الْغِفَارِيِّ وَأَبِي هُرَيْرَةَ وَأَنَسٍ