Allah's Messenger said: "When one of you comes to the Masjid, then let him perform two Rak'ah before sitting."
Jami` at-Tirmidhi Book 2, Hadith 168
← Previous Hadith "I met Abdullah bin al Husain in Makkah, so I asked him about this Hadith, so he narrated it to me, he said: 'When Allah's Messenger entered, he said (Rabbi aftahli abwaba rahmatik) 'O Lord, open the gates of Your mercy for me.' And when he exited he said: (Rabbi iftahli abwaba fadlik) 'O Lord, open the gates of Your blessings for me.'"

Jami` at-Tirmidhi Book 2, Hadith 167 Next Hadith → Allah's Messenger said: "All of the earth is a Masjid except for the graveyard and the washroom."

Jami` at-Tirmidhi Book 2, Hadith 169