The interpretation of verses 22-23 is difficult, and their place in the context is not easily defined. But they seem to make the most sense if taken as references to whatever distracts a person from full devotion to God, whether wealth (6.19-21, 24) or anxiety (6.25-34).

The eye is the lamp of the body is ambiguous; it may indicate either that the eye betrays what an individual is like inwardly, or that the eye gives light to the body. Scholars quote Jewish sources in support of the first interpretation. However, the closing sentence of verse 23 shows that more is intended than mere knowledge of a man’s heart through looking into his eye. Good News Translation therefore follows the second interpretation.

The Greek singular eye may be rendered as a plural, “eyes” (Good News Translation), and the equational statement, The eye is the lamp, can be restructured as a simile (Good News Translation “The eyes are like a lamp”). Bibel im heutigen Deutsch, 1st edition translates “The eye gives light to a person,” while the later Die Bibel im heutigen Deutsch has “The eye mediates light to a person.” Translators will find it useful to do something very similar to Good News Bible or either edition of Die Bibel im heutigen Deutsch. Some use full comparison, a combination of these two versions, and say “The eye is like a lamp that gives light to a person.” The order can be reversed: “A person’s eye provides light for his whole body (like a lamp).”

Sound is the word used by most translations, but the precise meaning is difficult to determine. By itself it contrasts with the Greek term for “twofold,” as if to say “singlefold.” It thus has the idea of simplicity, straightforwardness, or purity, and depending upon context it can mean “single,” “simple,” or “sincere,” that is, with no ulterior motive. In this context it contrasts with not sound, which is literally “if your eye is bad or evil.” In this sense the two expressions can describe eyes that are medically in good or in bad condition, the sound eye being “clear” or “healthy,” and the one that is not sound being unhealthy. But it is clear that in this context the terms are used figuratively for something else.

Since an “evil eye” is a Jewish metaphor for stinginess, some scholars argue that this “good eye” fits the metaphor for generosity. Note that in 20.15 the expression “evil eye” clearly means “greedy” (Good News Translation “jealous”). The context of verses 19-21 favors this understanding here. Barclay translates in a way that retains both the figure and this meaning: “sound and generous … diseased and grudging.”

Other scholars point out that in the Septuagint this word and its cognates represent a Hebrew word which means “singleness of purpose” or “undivided loyalty,” especially toward God. And the Aramaic counterpart to the Hebrew may mean both “undivided commitment” and “health.” The passage is then understood to mean that, just as blindness makes a person’s entire life one of darkness, so distraction by earthly riches blinds a person to God and leads to total darkness.

Matthew frequently uses parts of the body figuratively: verses 21-23 speak of the heart and eye, while 5.28, 30 speak of the eye, heart, and hand, 6.3 speaks of the hand, and 15.11 of the mouth. As the eye goes, so goes the entire person. If the eye is sound, one can see the light; if it is not sound, the entire individual walks in darkness. This means that if one’s eye for God is darkened, the total person gropes around in darkness. If a person lacks the ability to perceive the presence of God, how terribly dark it is!

Translators will do well to follow this interpretation. To say that an eye is sound means that it is healthy, that it is free from defect, or that it works properly. The eye that is not sound will be unhealthy, it will have defects, or it will not see as an eye should.

With a sound eye, then, your whole body will be full of light. This can probably be translated literally in many languages. It can also be stated as “Thus all of your body (or, being) will see the light” or “You will have light in your whole body (or, whole being).” In some cases, where the figure or image of a light means nothing, people will say “You will know (or, see) clearly what you are doing in every aspect of your life.”

Similarly, with unsound eyes, your whole body will be full of darkness. If a literal translation means nothing in a language, then translators may say “then all of you will see nothing, as if you were in darkness,” “your entire being will be in darkness,” or “you won’t know what you are doing in any aspect of your life.”

If then the light in you is darkness is practically a literal rendering of the Greek and results in a zero meaning. A few translations, however, do attempt to make some meaning of the text; for example, New English Bible (“If then the only light you have is darkness, the darkness is doubly dark”), Barclay (“If the light that ought to be in you has turned to darkness, what a terrible darkness that darkness is!”), and Bibel im heutigen Deutsch, 1st edition (“If what was supposed to give you light has become dark, how terrible then will that darkness be!”). The meaning seems to be “The eye is the organ through which light is supposed to come into the body. However, if the organ which was supposed to bring light into the body has gone bad, then the whole body is in terrible darkness.” This sentence is perhaps the key to the interpretation of verses 22-23: an analogy is made between the eye, which is intended to bring light into the body, and the “spiritual eye,” through which a person is supposed to perceive the light of God’s revelation.

Most translators will be able to use a sentence like those examples listed above: “If the thing that is supposed to give you light is instead darkness, how great your darkness is (or, how great is the darkness in which you are)” or “If the thing that is supposed to bring understanding to you, like a light, is dark, then you can’t understand anything, and the darkness in which you live is great.”

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .