Sahih Muslim | Book 1 | Hadith Number 239
Narrated by Abu Huraira
It is narrated on the authority of Abu Huraira that some people from amongst the Companions of the Apostle (may peace be upon him) came to him and said: Verily we perceive in our minds that which every one of us considers it too grave to express. He (the Holy Prophet) said: Do you really perceive it? They said: Yes. Upon this he remarked: That is the faith manifest.