The Messenger of Allah (may Allah bless him and grant him peace) said: “Every verse (of the Qur’an) has an outward and an inward (meaning).”
It was said to him: “Oh Messenger of Allah, we experience during your recitation a pleasure that we do not experience when anyone else recites.”
He said: “That is because you recite it for its outward and I recite it for its inward.”
For us, this means that when he (may Allah bless him and grant him peace) used to recite, he would be gazing at the Wisdom (i.e. the inner meanings of what he is reciting). The listener would find pleasure from his recitation, because that was a recitation that was clothed in the light of the Wisdom (i.e. the inner meanings).”
– Al-Hakim al-Tirmidhi (c. 205-298 Hijri, may Allah most great be pleased with him) in his book Kitab Ithbat al-‘Ilal, p. 74.