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. The light of the body is the eye - Or, the eye is the lamp of the body. See on Matthew 6:22 (note), etc.
The 35th and 36th verses are wanting in some MSS., and are variously read in others.