عن أبي فراس رجل من أسلم قال نادى رجل فقال يا رسول الله ما الإيمان قال الإخلاص. رواه البيهقي في شعب الايمان وهو مرسل (الترغيب و الترهيب 1/58)
Hadhrat Abul Firaas a person from the tribe of Aslam relates that a man once asked Rasululah (Sallallahu Alayhi Wasallam): “O Rasulullah (Sallallahu Alayhi Wasallam), what is Imaan? Rasulullah (Sallallahu Alayhi Wasallam) replied: “It is ikhlaas.” (Bringing true faith in Allah Ta’ala alone and doing every action for His pleasure in accordance to the prescribed manner).