We said, "Messenger of Allah, which aspect of Islam is best?"He replied, "That the Muslims are safe from his tongue and his hand."
أخبرنا سعيد بن يحيى بن سعيد الأموي عن أبيه قال حدثنا أبو بردة وهو بريد بن عبد الله بن أبي بردة عن أبي بردة
قلنا يا رسول الله أي الإسلام أفضل قال من سلم المسلمون من لسانه ويده
It was reported by Bukhari, in the Book of Faith, chapter "Which aspect of Islam is best?", no. 11, and Muslim, in the Book of Faith, chapter "Explaining the different degrees of excellence in Islam and which of its matters is best", no. 42, from Saeed bin Yahya, through him.