Bede the Venerable
Catena Aurea · Lukasevangelium 11
No man, when he hath lighted a candle, putteth it in a secret place, neither under a bushel, but on a candlestick, that they which come in may see the light. The light of the body is the eye: therefore when thine eye is single, thy whole body also is full of light; but when thine eye is evil, thy body also is full of darkness. Take heed therefore that the light which is in thee be not darkness. If thy whole body therefore be full of light, having no part dark, the whole shall be full of light, as when the bright shining of a candle doth give thee light.
Our Lord here speaks of Himself, shewing that although He had said above that no sign should be given to this wicked generation but the sign of Jonas, yet the brightness of His light should by no means be hid from the faithful. He Himself indeed lights the candle, who filled the vessel of our nature with the fire of His divinity; and this candle surely He wished neither to hide from believers, nor to place under a bushel, that is, enclose it in the measure of the law, or confine it within the limits of the single nation of the Jews. But He placed it upon a candlestick, that is, the Church, for He has imprinted on our foreheads the faith of His incarnation, that they who with a true faith wish to enter the Church, might be able to see clearly the light of the truth. Lastly, He bids them remember to cleanse and purify not only their works, but their thoughts, and the intentions of the heart. For it follows, The light of the body is the eye.