Matthew 6:22-23 is sandwiched between two passages explicitly about wealth, and the three passages together form a unit with 6:25-34 which is related to possessions and the necessities of life. The logical flow is:
- 19-21 Do not be short-sighted (seek treasure that will last)
- 22-23 ?
- 24 Do not be double-minded (you cannot serve God and money)
- 25-34 Do not be anxious (seek righteousness and your material needs will be met)
This indicates that we should at least consider the possibility that there is a link to wealth in 22-23 as well.
2. Internal logic
The phrase "The eye is the lamp of the body" can be interpreted in two ways. Either the eye, belonging to the body, shines outward (like the headlight of a car), or the eye is the light that enlightens the body itself, ie it shines inward. The latter interpretation is key to understanding Jesus' logic because the condition of the eye/lamp is what determines whether the "whole body will be full of light/darkness".
The two remaining exegetical questions concern the two metaphors used:
- What does it mean here for the eye to be either 'healthy' or 'bad'
- What is the meaning here of 'darkness' and 'light'
4. Light and darkness
There is a general association between light and good, and darkness and evil, throughout scripture.
The only other mention in the Sermon on the Mount fits the pattern of light corresponding to what is good:
14“You are the light of the world. A city set on a hill cannot be hidden. 15Nor do people light a lamp and put it under a basket, but on a stand, and it gives light to all in the house. 16In the same way, let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven. Matthew 5, ESV
5. Healthy or bad eyes
The NET Bible translation notes indicate that the word used for 'bad' can also mean “evil”. This allows the possibility that Jesus is consciously alluding to Proverbs 28:22:
A stingy man hastens after wealth and does not know that poverty will come upon him. ESV
... because the phrase 'A stingy man' is literally 'A man whose eye is evil'
What is being said here. Does the eye and light symbolise something or can it be taken literally?
- These verses are about wealth like the surrounding context.
- Jesus is alluding to a Hebrew proverb and idiom concerning those whose 'eye is evil' or 'are stingy'
- If a man is stingy (ie seeking after worldly wealth for himself), he is poisoning his soul. seeking after what is good instead improves his internal condition.