"For the commandment is a lamp and the teaching is a light;and reproofs for discipline are the way of life"
God is giving us a metaphor to understand why He has given us commandments, teachings, and rebukes.
for the commandment is a lamp
He tells us that the commandment is a lamp or that which contains the light and holds the light. It can, in some cases, focus the light but not usually in Ancient Israel.
the teaching is a light
The teaching is the light. This is the explanation of the commandments that come following God's moral boundaries. There is far more contained in each commandment than just the surface words of the commandment. There is its meaning in different situations. There are the exceptions implied through the use of the words in the commandment. There are the specific places where one crosses from good to evil in their conduct because of the commandment. There are the various places that the commandment applies and the various ways that it applies. There is also the opposite of the negative commandment – the positive action that is also commanded in the commandment.
and reproofs for discipline are the way of life
The reproofs for discipline are a way of life. The idea is that the rebukes that God has built into life through laws of nature, laws of civilization, social rules, etc., mark the edges of the path of righteousness. You have to blow through all the rebukes in your life to stay outside of the path of righteousness. This proverb is saying: don't do it.
God is marking out the edges of the path of life for you with the rebukes that He is sending your way. They could be physical rebukes, financial rebukes, vocational rebukes, marital rebukes, social rebukes, etc. Stop resenting these rebukes but welcome them as the only way God could clearly mark out the edges of the right path.
This is much like what James tells us in James 1:2-4. God is for us and He has given us the lamp, the light, and the markings for the edge of the path. Right now are you trying to push past a rebuke in a particular area? Stop and think.
Now it is also instructive that God says that it is only those reproofs that are for discipline that mark the edge of the path of life. There are all kinds of people who want to rebuke us when we don't do things their way. These rebukes do not mark anything except the little box that others want to keep us in. We should push through those. The word discipline is the word for instruction or we would say, in this context, constructive criticism. God has rebukes that do these, society has these, our friends have these. All these together mark out the edges of our particular path of righteousness or life.
It is amazing but with all of these together, it is an individual path for each one of us. God sends reproofs or spankings into our life to let us know that something is wrong and needs to be changed.
The reproofs could be relationally: marital problems, friendship difficulties.
They could be financial problems: not enough money, lawsuits, defective merchandise.
They could be spiritual: spirits, distance from God, guilt.
They could be mental: confusion.
The problem with our society is that we don't recognize the reproofs as spankings. We think of them as just normal life because everybody else is having the reproof also.