10 And we, who see in one way, and hear in another way, how know we this? We return perhaps to ourselves, if we are not the trangressors to whom it is said, “Return, O trangressors, to your heart.” Return to your heart: why go from yourselves, and perish from yourselves? Why go the ways of solitude? You go astray by wandering: return. Where? To the Lord. 'Tis quickly done: first return to your own heart; you have wandered abroad an exile from yourself; you know not yourself, and yet you are asking by whom you were made!
Return, return to your heart, lift yourself away from the body: your body is your place of abode; your heart perceives even by your body. But your body is not what your heart is; leave even your body, return to your heart. In your body you found eyes in one place, ears in another place: do you find this in your heart? Or have you not ears in your heart? Else of what did the Lord say, “Whoso has ears to hear, let him hear?” Or have you not eyes in your heart? Else of what says the apostle, “The eyes of your heart being enlightened?” Return to your heart; see there what, it may be, you can perceive of God, for in it is the image of God.
In the inner man dwells Christ, in the inner man are you renewed after the image of God, in His own image recognize its Author. See how all the senses of the body bring intelligence to the heart within of what they have perceived abroad; see how many ministers the one commander within has and what it can do by itself even without these ministers. The eyes report to the heart things black and white; the ears report to the same heart pleasant and harsh sounds; to the same heart the nostrils announce sweet odors and stenches; to the same heart the taste announces things bitter and sweet; to the same heart the touch announces things smooth and rough; and the heart declares to itself things just and unjust.
Your heart sees and hears and judges all other things perceived by the senses; and, what the senses do not aspire to, discerns things just and unjust, things evil and good. Show me the eyes, ears, nostrils, of your heart. Diverse are the things that are referred to your heart, yet are there not diverse members there. In your flesh, you hear in one place, see in another; in your heart, where you see, there you hear. If this be the image, how much more mightily He whose the image is! Therefore the Son both hears and sees; the Son is both the hearing itself and the seeing: to hear is to Him the same thing as “to be;” and to see is to Him the same thing as “to be.” To see is not the same thing to you as to be; for if you lose your sight, you can be; and if you lose your hearing, you can be.
Source: Tractates on the Gospel of John (New Advent)