Bismillah Walhamdulillah Was Salaatu Was Salaam ‘ala Rasulillah
Narrated Abu Qatada bin Rabi Al-Ansari (Radi-Allahu ‘anhu):
The Prophet (Sallallahu ‘Alaihi Wa Sallam) said, “If anyone of you enters a Masjid, he should not sit until he has offered a two-Rakat prayer.”
Bukhari Vol. 2 : No. 264