Does Vaping Break Your Fast?, Sayyid Kashmiri explains that, according to Sayyid Sistani, both vaping and smoking invalidate the fast as a matter of obligatory precaution. Can Muslims Smoke? Studio Arabiya In Islam, smoking and vaping are generally considered sinful because they harm the body, waste money, and can harm others all of which are prohibited principles in the Quran and Sunnah but many Can Muslims Smoke Weed?