Surah 26. Ash-Shuara, Ayah 113

This is obviously a retort to the unbelievers' suggestion (elliptically implied here) that those "abject" followers of Noah had declared their faith in him, not out of conviction, but only in order to gain some material advantages. Noah's answer embodies a cardinal principle of Qur'anic ethics and, hence, of Islamic Law: No human being has the right to sit in judgment on another person's faith or hidden motives; whereas God knows what is in the hearts of men, society may judge only by external evidence (az-zahir), which comprises a person's words as well as deeds. Thus, if anyone says, "I am a believer", and does not act or speak in a manner contradicting his professed faith, the community must consider him a believer.