What secret it was that made the Messenger (the communication with God and Peace are through him) apprise of the time of cupping to be in the springtide with the progression of the lunar month from only the seventeenth day until the twenty-seventh day of it.
We know that the moon has a pull effect on the earth despite its little diameter (3478 km),and its mass constitutes one part out of (80) parts of the mass of the earth, and the distance of it from the earth is a distance of (385.000 kms), this short distance makes its pulling force have a great influence on the oceans where they rise to form the tide, even the earth’s crust is never free from these effects. The crust of the north American continent heaves up to fifteen centimeters when the moon interposes its sky. The moon has also another effect which helps sap to rise in its circulation in the high trees.
The two French professors (Jubet and Galieh de Fond) noticed that the moon has an effect on animals from its birth as a crescent until it becomes a full-moon. The sexual activates increase gradually in animals, poultry and birds. They also noticed that poultry give more eggs in this period more than the period of senility when the moon begins its gradual atrophy to hunchback phase, then to the last lunar quarter, and to waning. According to special notice, it is found that there is a period of activity and much energy in animals connected with the lunar stages. They also noticed that poultry and some domesticated animals, and fishes, animals and lobsters of the Indian Ocean and the Red Sea produce more eggs in certain periods of the moon faces.
The moon reaches the climax of its effect when it is full-moon. It affects blood pressure producing higher level of pressure and in stimulating the blood circulation, so the sexual craving is excited. Also some western countries suffer much from the increase in the rate of crimes and assaults in nights and days of the full-moon.
During the first days of the lunar month, i.e. from the first day until of the fifteenth day, blood-flow is stimulated and it reaches its maximal limit and eventually it pokes all the blood residues and impurities which precipitated along the walls of the deep and superficial and in all the ramifications of the blood vessels in the tissues (exactly as, in turn, it – as a big spoon- stirs the water of the seas so as the salts in them don’t precipitate).
Likewise, when the moon begins to decrease from (17 – 27), the blood can carry these residues and impurities to the calmest parts of the body where they settle in the shoulder blades area. The tide of the seas due to the lunar pull begins to weaken from 17 to 27 of the lunar calendar. Since the cupping operation is performed in the morning after sleep and rest for the body and the blood circulation, and the moon is still rising despite the sunrise in the morning. The moon will have a little tidal effect during the performance of cupping. This situation is very good for our work for the moon still has the effect of pulling the blood from inside to the outside (the inner blood of the peripheral blood and the peripheral blood surrounding the opening of the cup). This situation has an excellent effect in performing a successful and profitable cupping operation to release the body from its impure blood.
If the cupping operation is performed in the middle of the lunar days (12-13-14-15), the strong pull of the moon stimulates the blood, and the blood will lose much of its young corpuscles, the Merciful God does not wish that for his servant-mankind. But the first days of the moon (crescent) do not let it do its job in carrying the blood residues and impurities from the inside to the outside in order to gather in the upper part of the back as it has been mentioned before.
Ref: Mohammad Amin shekho