a devil, as the Messenger of Allah (peace and blessings be upon him) explained when he was asked, “What is the difference between the red dog, the white dog, and the black dog?” He replied, “The black dog is a devil.” If such a black dog passes in front of someone who is praying, it breaks the prayer and the worshipper must begin again. The same applies if it walks between the worshipper and his sutrah (prayer-screen): it nullifies the prayer and he must repeat it from the start.
According to most scholars, it is unlawful to hunt with a black dog. Even if the dog is trained, released by its owner, and the owner pronounces Allah’s name, the game is still prohibited, for the black dog is deemed a devil. Just as the quarry of human unbelievers—apart from Jews and Christians—is not lawful, so too the catch taken by this “devil-dog” is invalid. Dogs of other colors, however, do not invalidate the prayer, and hunting with them is permissible provided the well-known legal conditions are met.
Keeping a dog without a valid exemption is forbidden and counts among the major sins—Allah’s refuge is sought—because anyone who keeps a dog, except for the specified cases, loses two qirāts of his reward every single day. The Prophet (peace and blessings be upon him) said, “Whoever follows a funeral until the burial is completed will receive two qirāts.” When asked, “What are the two qirāts?” he replied, “Like two enormous mountains; the smaller of them is the size of Mount Uhud.” Thus, a person who keeps a dog outside the permitted exceptions forfeits each day a reward comparable to two Mount Uhuds—two full qirāts. This shows that owning dogs is a major sin except for the three cases: hunting, tillage, and livestock.
“Hunting” refers to a trained dog that a person uses for game. Its catch is lawful only if the dog is properly trained—running when released, stopping when restrained, and refraining from eating the prey—and the owner pronounces Allah’s name when releasing it. In such circumstances the game is permissible, and the person keeps the dog out of genuine need and benefit.