Shama-il Tirmidhi Chapter 49, Hadith Number 5 (347).

Anas bin Maalik Radiyallahu ‘Anhu said: “Rasulullah Sallallahu ‘Alayhi Wasallam used the treatment of cupping on both sides of his mubaarak neck and between both shoulders, and generally took this treatment on the seventeenth, nineteenth or the twenty first of the (lunar) month”.

In some ahaadith, the benefit of these dates are also mentioned. The unaani hakims also agree with this. It is reported that Ibn Sina said it is not beneficial to take treatment of cupping in the beginning and end of the month, this treatment should be taken in the middle of the (lunar) month. From this hadith we find that Sayyidina Rasulullah Sallallahu ‘Alayhi Wasallam took this treatment many times, and on different days, and from the ahaadith that follow, we also find that it was taken at different places. The Jews gave Sayyidina Rasulullah Sallallahu ‘Alayhi Wasallam strong poison in his food. They intended to kill him, so that the question of their opposition may be eliminated. Although Sayyidina Rasulullah Sallallahu’Alayhi Wasallam did not eat the whole portion of the poisoned meat, but the effect of the portion eaten was, that it used to trouble him at different times, especially in the summer the effects used to occur frequently. The place where it used to pain the treatment of cupping was applied. As poison mixes into the blood stream, its effects and pains are felt on different parts of the body.