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.
Now when He adds, If thy whole body therefore, &c. by the whole of our body He means all our works. If then thou hast done a good work with a good intention, having in thy conscience nothing approaching to a dark thought, though it chance that thy neighbour is injured by thy good actions, nevertheless for thy singleness of heart shalt thou be rewarded with grace here, and with glorious light hereafter; which he signifies, adding, And as the bright shining of a candle shall it give thee light. These words were especially directed against the hypocrisy of the Pharisees, who sought for signs that they might catch him.