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.  

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

Muhayyisah asked permission of the Messenger of Allah ﷺ regarding hire of the cupper, but he forbade him. He kept on asking his permission, and at last he said to him: Feed your watering camel with it and feed your slave with it.  

أَنَّهُ اسْتَأْذَنَ رَسُولَ اللَّهِ ﷺ فِي إِجَارَةِ الْحَجَّامِ فَنَهَاهُ عَنْهَا فَلَمْ يَزَلْ يَسْأَلُهُ وَيَسْتَأْذِنُهُ حَتَّى أَمَرَهُ أَنِ اعْلِفْهُ نَاضِحَكَ وَرَقِيقَكَ  

The Messenger of Allah ﷺ got him self cupped and gave the cupper his wages. Had he considered it impure, he would not have given it (wage) to him.  

احْتَجَمَ رَسُولُ اللَّهِ ﷺ وَأَعْطَى الْحَجَّامَ أَجْرَهُ وَلَوْ عَلِمَهُ خَبِيثًا لَمْ يُعْطِهِ  

That Abu Tibah cupped the Messenger of Allah ﷺ and he ordered that a sa' of dates be given to him, also ordering his people to remit some of his dues.  

أَنَّهُ قَالَ حَجَمَ أَبُو طَيْبَةَ رَسُولَ اللَّهِ ﷺ فَأَمَرَ لَهُ بِصَاعٍ مِنْ تَمْرٍ وَأَمَرَ أَهْلَهُ أَنْ يُخَفِّفُوا عَنْهُ مِنْ خَرَاجِهِ