The lamp of the body is thine eye when thine eye is simple, thy whole body also is light; but when it is wicked, thy body also is dark.
The Lord has just spoken of a lamp lit and set where everyone who comes in can see the light. Now He turns from the lamp outside to the eye inside, and to the whole state of the person. (Older translations say "single" where the ESV says "healthy".)
The verse calls the eye a lamp. But what kind of lamp?
The eye is the lamp of the body; not the light, but what holds and fixes the light. The light comes from elsewhere. The organ that perceives does not create the light; it receives it. The light for us is in the Word alone; it judges and makes plain… With the heart set on things above, the eye is single and clear. God is before it, and in His light we see light. Then the whole body becomes full of light: the hands and feet have plenty of it for work and walk.
But another writer names the light. It is not a thing but a Person.
The light is not something we have in ourselves; it does not exist in the eye. The eye is the organ that admits the light from outside. It must be a good and sound eye that does not shrink from the light, if the light is to be of any use to us… The Light, the candle that God's own hand has lit for us, is the Lord Himself, our Saviour.
So what makes an eye "single"? The word itself is the clue.
The word "single" must be understood as "plain, pure." … It is the simplicity and singleness of heart marked by love and trust. Such a heart will not allow any sin — even doubting or wicked hidden motives — to spoil our relationship with our Lord and our God and Father.
Luke's account presses man's condition. A perfect lamp changes nothing for an eye that cannot use it.
But Luke always brings in man's state, or moral condition. Light alone outside does not enable a man to see. If the eye is physically powerless, the light makes no impression… It is a question here of moral purpose. If nothing divides the heart's attention, if Christ fills the field of vision, the whole body is light… And is there not evil in looking away from Christ to other objects? Is it not evil to turn away from the only One who is worthy?
The crowd around Him had already shown the bad eye. They asked Him for a sign.
The light was shining, yet they asked for light. That is what a sign meant — something to make plain to them who the Lord was… It was as though a man walked into a room at midnight where a candle was burning brightly. He said he must have a sign, some proof that it was a candle. But why were they like that? The light that shone hurt their evil eye and they did not like it. They wanted something that would make them comfortable in their sins.
The verse promises light to a single eye. So what does lasting confusion tell us?
Now, if my body is full of light, can my mind be full of perplexity? Impossible. The two things cannot go together. So when someone lives "in dark uncertainty," it is very plain his eye is not single. He may seem very sincere. He may want very much to be guided right. But he may be sure of this: the single eye is missing — and God's guidance requires it.
That test cuts deeper than the decision in front of us.
So it is God's will — a blessed will — that we can read His will only as far as our own spiritual state allows. As a rule, when we think we are judging circumstances, God is judging our condition… He would not be good to us if He let us find out His will any other way.
What fills a person spreads.
Light does not only show itself; it lights up everything around it. If God's light were in the soul, the soul would be full of it and no part dark.
But there is a reverse side. Light we refuse does not stay neutral.
God will always guide the obedient, humble soul. But if we do not walk by the light He gives, we shall get into darkness. Light not acted on becomes darkness, and oh, "how great is that darkness"! Nothing is more dangerous than tampering with the light God gives.
- Light first. The eye makes no light; it admits it. The light here is Christ Himself, already shining.
- Eye second. A perfect lamp helps nothing if the eye is bad. The verse tests you, not the light.
- Single means one. The word means plain and pure — one object filling the view, with no rival dividing the heart.
- Full means clear. A single eye fills the whole body. Hands and feet have light for work and walk. Lasting confusion says the eye is not single.
- Full means shining. Light received does not stay private. It lights everything around it. Light refused turns to darkness.
See therefore that the light which is in thee be not darkness.
Commentary for this verse has not been generated yet.
If therefore thy whole body [is] light, not having any part dark, it shall be all light as when the lamp lights thee with its brightness.
Jesus has just warned that the lamp of the body is the eye, and that light itself can turn into darkness inside a person. Verse 36 gives the bright side of that warning. A life with nothing held back shines like a lamp lighting up the room.
The picture rests on a difference between the source of light and the organ that takes it in.
The eye is the lamp of the body; not the light, but what holds and fixes the light. The light comes from elsewhere: the organ of perception does not create the light, but receives it. The light for us is in the Word alone; it is this that judges and makes plain. But there must be spiritual reception, and for this, capacity of reception... With the heart set on things above, the eye is single and clear: God is before it, and in His light we see light. Then the whole body becomes full of light: the hands and feet have plenty of it for work and walk.
The word behind "healthy" or "single" is rare, and its family of related words helps fix the sense.
The word "single" must be understood as "plain, pure". In the whole New Testament it only appears in Matthew 6:22 and in the parallel passage in Luke 11:34-36. The corresponding noun "singleness" (simplicity) appears more often... It is the simplicity and singleness of the heart, marked by love and confidence. It will not allow any sin — even doubt or wicked hidden motives — to spoil our relationship with our Lord and our God and Father. If the heart is single towards Christ, the spiritual life will be full of light. This light has its source in God. It helps the youngest believer to understand the Word of God and to put it into practice.
The phrase describes a life with no locked rooms — and this openness is what produces the shining.
The moral progress in this passage is very fine. There is first the single eye — the one simple, firm, earnest purpose of the heart to go straight on in the path of obedience, cost what it may. Then the body is full of light. What more can there be? But there is something more, for there is certainly nothing unnecessary in Scripture. "If your whole body is full of light, having no part dark" — then "it will be wholly bright." That means no reserve, no chamber of the heart kept locked up for the sake of friends, self-interest, worldly ease or anything else. You become transparent, and your light shines so others see it. Not that you think so, for a single eye never looks at self. If I make it my object to be a light-bearer, I shall get full of darkness and be a stumbling-block.
The verse ends with the image of a lamp shining.
So when one has light for oneself, it becomes the means of light for others. In divine things you cannot separate power for others from testimony to the glory of God.
The condition attached is honesty across the whole of life, not only in the parts we are willing to inspect.
If our whole body is full of light, having no part dark — everything subject to the light that enters — then all will be full of light, as from the bright shining of a lamp. That lamp is the testimony of Christ. There must be honest willingness to receive the light in every department of one's life. Then the result will be fullness of light in the soul. Faith will be rewarded with clear, genuine knowledge from Him who is light.
The promise is a body fully lit. So one writer treats lasting confusion about God's path as a symptom, not bad luck.
It is my privilege to be as sure that I have my Master's mind about my path as that I have His Word for the safety of my soul... Now, if my body is full of light, can my mind be full of perplexity? Impossible. The two things are completely incompatible. So when someone is plunged in dark uncertainty, it is very plain that his eye is not single. He may seem very sincere. He may be very anxious for right guidance. But he may be sure there is a lack of a single eye — that indispensable requirement for divine guidance.
The reverse case, drawn from the warning of verse 35, sharpens the contrast the verse is making.
What a contrast between a man who has a single eye and a man who does not act on the light God has given him! The one has his body full of light; the other has his body full of darkness. The one has no part dark; the other is plunged in thick darkness. The one is a light-bearer for others; the other is a stumbling-block in the way.
- Source. The eye does not create light; it receives it. The light comes from the Word and from the testimony of Christ. The eye only holds and fixes it.
- Single. The word means plain and pure — one object, one purpose, a heart that keeps no hidden motive in reserve.
- Whole. "No part dark" means no locked chamber kept back for friends, self-interest or ease. The light must reach every department of life.
- Shine. Light kept for yourself does not stay yours. Once the whole is lit, the person becomes transparent, and others see it — though a single eye never looks at itself.
- Result. Where the eye is single, guidance is as sure as the safety of the soul. Where self is the object, the same person becomes a stumbling-block instead of a lamp.