The Prophet ﷺ said: The earnings of a cupper are impure, the price paid for a dog is impure, and the hire paid to a prostitute is impure. (Using translation from Abū Dāʾūd 3421)  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ «كَسْبُ الْحَجَّامِ خَبِيثٌ وَمَهْرُ الْبَغِيِّ خَبِيثٌ وَثَمَنُ الْكَلْبِ خَبِيثٌ»