Those upholding the Shariah and those in a position to explain its legislative rules ought to take a firm stand to prevent deviations and discrepancies by teaching and guidance that will eradicate them and expose superficial ideas and corruption. It is reported in a Tradition that the Prophet (peace be upon him) said to Abd Allah ibn Amr ibn al-As: "I have been informed that you pray all night and fast during the day!" Abd Allah said, "I answered: '(Yes) I do.'" The Prophet then said: "If you do so, your eyesight will become weak and you will become weak. There is no doubt that your body has a right over you, and your family has a right over you. So fast (for some days) and do not fast (for some days), and pray for some time and then sleep." [Bukhari]
When abnormalities are confined to the person committing them, moral exhortation and proper education are the means to dealing with them. If, on the contrary, they infringe upon others and cause harm to them either by word or action, such as calling people to follow these fancies, punishment is the remedy. Accordingly, it is the duty of the ruler (wali al-amr) to compel those abandoning work to work in order to provide for their families and to deport those inviting others to their innovations and fancies, as Umar did when he deported Subaygh from Basra. Umar also compelled traders hoarding food to sell what people needed of the various provisions, as narrated in the Muwatta, although selling and buying is in principle permissible, since its permissibility is rooted in people's natural impulse for acquisition and the pursuit of profit. Thus, it is the difference of purpose that is taken into consideration in the course of action.
Compiled From: "Treatise on Maqasid Al-Shariah" - Ibn Ashur, pp. 111, 112