Prayer: The Prayer for Saluting the Mosque
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 899
It is recommended that when a person enters a mosque, he should perform a two rakʿah prayer with the intention of saluting (taḥiyyah) and respecting (iḥtirām) the mosque; and if he performs an obligatory prayer or another recommended prayer, it is sufficient.