Sunan an-Nasā'ī 4286✓ 5Sahih
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّهُ سَمِعَهُ يَقُولُ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَنْ أَمْسَكَ كَلْبًا إِلاَّ كَلْبًا ضَارِيًا أَوْ كَلْبَ مَاشِيَةٍ نَقَصَ مِنْ أَجْرِهِ كُلَّ يَوْمٍ قِيرَاطَانِ " .
It was narrated that Ibn 'Umar said:"The Messenger of Allah said:' whoever keeps a dog except one that is trained for hunting or a dog for herding livestock, two Qirats will be deducted from his reward each day