Prayers (Salat)
Bukhari :: Book 1 :: Volume 8 :: Hadith 386
Narrated Anas bin Malik:
Allah's Apostle said, "Whoever prays like us and faces our Quibla and eats our slaughtered animals is a Muslim and is under Allah's and His Apostle's protection. So do not betray Allah by betraying those who are in His protection."