Prayer: Disapproved Actions in a Mosque
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 900
The following are disapproved for a person to do in a mosque: sleep (unless he is compelled to), talk about worldly affairs, engage in craft, recite poetry (unless it exhorts people to good), and similar things. It is also disapproved to discharge nasal mucus, saliva, and phlegm in a mosque; in fact, this is unlawful in some cases. Furthermore, it is disapproved to look for something lost or raise one’s voice in a mosque; however, there is no problem in raising one’s voice for adhān.