It seems that He is not here speaking of the bodily eye, or of the outward body that is seen, or He would have said, If thine eye be sound, or weak; but He says, “single,” and, “evil.” But if one have a benign yet diseased eye, is his body therefore in light? Or if an evil yet a sound, is his body therefore in darkness?
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).