Verily, those who have attained to faith and do good works, and are constant in prayer, and dispense charity - they shall have their reward with their Sustainer, and no fear need they have, and neither shall they grieve.
Al-Baqara (The Cow) Verse 277
Allah's Apostle said, "If anyone of you enters a mosque, he should pray two Rakat before sitting."
Sahih Bukhari: Volume 1, Book 8, Number 435