سنن ابن ماجه

It was narrated from ‘Abdullah bin Mughaffal that the Messenger of Allah (ﷺ) said: “Were it not that dogs form one of the communities (or nations – of creatures), I would have commanded that they be killed. But kill those that are all black. There are no people who keep a dog, except for dogs used for herding livestock, hunting or farming, but two Qirat will be deducted from their reward each day.”