Prayer: Preparing a Mosque for Mourning Ceremonies
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 893
If for the purposes of holding mourning ceremonies a mosque is draped in curtains and covered in rugs and black cloth, and if utensils for serving tea are brought into it, then as long as these actions do not damage the mosque or obstruct the performing of prayers in it, there is no problem.