This proverb could be literally translated: “To light a lamp for a blind person is to waste gas.”
We can not say how important it is for people to have light. Here in Haiti, electric power is inconsistent. We often do not have current at night. That can make life difficult. When there is no electricity and no other battery lights, people use kerosene in lamps to have light so that they can keep on doing their activities or just be comfortable. But whether it is day or night, dark or bright, clarity or obscurity, that doesn’t make any difference to the blind person. He/she still cannot see. Having light just does not better his situation.
Haitians say this proverb to represent the situation of someone advising stubborn and arrogant people. A person who will not listen to instruction will do what they plan to do whether it is wrong or right, even though we try to persuade them not to do it. So it is a waste of time and energy trying to help them see the light.
Proverbs 27:12 tells us that a prudent person foresees danger and takes precautions, while the simpleton goes blindly on and suffers the consequences. Let us be wise and open to learning and ready to give up an endeavor/action/idea if it reveals itself to be wrong or erroneous.