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  

Malik related to me from Ibn Shihab from Ibn Muhayyisa al-Ansari, one of the Banu Haritha, that he asked permission from the Messenger of Allah ﷺ to give payment for cupping, and he forbade him to do it. He continued to ask and seek his permission until he said, "Feed the ones who drive your water-carrying camels," meaning "your slaves."  

أَنَّهُ اسْتَأْذَنَ رَسُولَ اللَّهِ ﷺ فِي إِجَارَةِ الْحَجَّامِ فَنَهَاهُ عَنْهَا فَلَمْ يَزَلْ يَسْأَلُهُ وَيَسْتَأْذِنُهُ حَتَّى قَالَ اعْلِفْهُ نُضَّاحَكَ يَعْنِي رَقِيقَكَ  

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. (Using translation from Abū Dāʾūd 3422)   

أَنَّهُ اسْتَأْذَنَ رَسُولَ اللهِ ﷺ فِي إِجَارَةِ الْحَجَّامِ فَنَهَاهُ عَنْهَا فَلَمْ يَزَلْ يَسْأَلْهُ فِيهَا حَتَّى قَالَ لَهُ اعْلِفْهُ نَاضِحَكَ وَأَطْعِمْهُ رَقِيقَكَ