Sahih Muslim Book 1, Hadith Number 64.

Chapter : Concerning the eminence of Islam and of the affairs which are excellent.

‘Abdullah b. Amr b. al-As is reported to have said: Verily a person asked the Messenger of Allah (may peace and blessings be upon him) who amongst the Muslims was better. Upon this (the Holy Prophet) remarked: From whose hand and tongue the Muslims are safe.