It was narrated that Abu Dharr said: “The Messenger of Allah صلی اللہ علیہ وآلہ وسلم said: ‘When any one 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 صلی اللہ علیہ وآلہ وسلم just like you asked the and He said: ‘The black dog is a Shaitan.” (Sahih)