http://www.muftisays.com/blog/abu+mohammed/152_29-09-2009/hadith-on-cupping-_-hijama.html
View the post above to see the ample Hadith regarding Cupping.
As Muslims, it is very important to have the correct belief in Allah. He is the One who cures us when we are sick. It is also from the Sunnah to seek and take the remedy. So we do not fall into two common errors.
The first is not to take the remedy when we know it can help cure us by the will of Allah. The second is that we believe that only the remedy or medicine will cure us. Here, we would fall into a major sin because it is Allah who is the Curer and if He wills we are cured and if He wills we are not. We should believe that only Allah is the Curer otherwise we may fall into shirk (associating partners with Allah).
Therefore, we seek and take the remedy and put out trust in Allah by asking Him to cure us and believing that only He is the Curer.
The Messenger (SAW)would say,
"وَاشْفِ أَنْتَ الشّافِي لا شِفَاءَ إلا شِفَاؤُك".
".And cure us for You are the Curer, there is no cure but Your cure"
[Saheeh Al-Bukhaaree and Saheeh Muslim].
‘Abdulrahman as-Sa’di (may Allah have mercy on him) likewise shows that we should not rely too much on medicine as though it is the only remedy that can cure us. Rather Allah has made a cure in other aspects that we may not even realise. For example, the story of Yusuf’s u father who was given a piece of clothing from Yusuf u. When Yusuf’s u father smelt his son’s fragrance, he regained his eyesight and he was cured. The fragrance of Yusuf was a cure for his father’s eyesight. Allah was able to cure Yusuf’s u father without a reason but Allah is All-Wise. Similar to this is the story of Ayub u whereby no medication or doctors were able to cure his skin condition. Allah ordered him to hit the ground hard with his foot such that pure water would gush out. Allah then ordered him to drink from it and have a bath from that water. So Allah removed the harm internally and externally from him and Ayub u was cured. Therefore, Allah cures His servants by either clear apparent reasons such as medication or by other not so apparent reasons that even the human intellect cannot comprehend.
Allah said:
وإن يمسسك الله بضر فلا كاشف له إلا هو
And When Allah wills that you are inflicted with harm there is no one to remove it but him
[Soorah al-An’aam:17]
[Taken from Bahjatu Quloob al-Abraar by Sheikh ‘Abdulrahman as-Sa’di (may Allah have mercy on him) p.24 summarised].