1 Samuel 26:6 Then David said to Ahimelech the Hittite, and to Joab’s brother Abishai the son of Zeruiah, “Who will go down with me into the camp to Saul?” And Abishai said, “I will go down with you.” So David and Abishai went to the army by night. And there lay Saul sleeping within the encampment, with his spear stuck in the ground at his head, and Abner and the army lay around him. Then Abishai said to David, “God has given your enemy into your hand this day. Now please let me pin him to the earth with one stroke of the spear, and I will not strike him twice.” But David said to Abishai, “Do not destroy him, for who can put out his hand against the Lord’s anointed and be guiltless?” And David said, “As the Lord lives, the Lord will strike him, or his day will come to die, or he will go down into battle and perish. The Lord forbid that I should put out my hand against the Lord’s anointed. But take now the spear that is at his head and the jar of water, and let us go.” So David took the spear and the jar of water from Saul’s head, and they went away. No man saw it or knew it, nor did any awake, for they were all asleep, because a deep sleep from the Lord had fallen upon them.
Isaiah 29:10 For the LORD has poured out upon you a spirit of deep sleep, and has closed your eyes (the prophets), and covered your heads (the seers).
Isaiah 44:18 They know not, nor do they discern, for he has shut their eyes, so that they cannot see, and their hearts, so that they cannot understand.
2 Corinthians 4:4 In their case the god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the image of God.
2 Thessalonians 2:9-12 The coming of the lawless one is by the activity of Satan with all power and false signs and wonders, and with all wicked deception for those who are perishing, because they refused to love the truth and so be saved. Therefore God sends them a strong delusion, so that they may believe what is false, in order that all may be condemned who did not believe the truth but had pleasure in unrighteousness.
Acts 28:26-27 “‘Go to this people, and say, “You will indeed hear but never understand, and you will indeed see but never perceive.” For this people’s heart has grown dull, and with their ears they can barely hear, and their eyes they have closed;
We have many examples of God causing the eyes of man to be closed for a heavy sleep or so that they have no perception, understanding, or knowledge. We also have examples of satan sending false delusions and blinds those from seeing the light of the Gospel. In any case, those who are blinded have previously chosen to refuse to believe. In their heart, soul, and mind they have rejected God of heaven and chosen to believe the lies of the god of this world.
Spurgeon – The practice of blinding men is a horrible process, too horrible for us to say another word about it; but there is also spiritual blindness which comes on some men. These are, to begin with, unbelievers. The god of this world does not blind believers, but he blinds the minds of those who do not believe. It is, therefore, a very dangerous thing not to believe in the Son of God. The penalty of unbelief is death and condemnation; and that penalty begins to fall on men when, as a result of their unbelief, their foolish heart is darkened, their intellect loses the power to perceive spiritual objects, and the god of this world blinds their mental vision. Ah, my hearers, how anxious Satan is to secure your destruction, since, rather than that you should see the saving light, he takes the trouble to blind your eyes!
A man may be a very keen politician; he may be a first-rate man of business; he may be an eminent scientist, a profound thinker, and yet he may be blinded concerning spiritual truths. How often is it true, “You have hidden these things from the wise and prudent, and have revealed them to babes!” As an old writer says, “Poor, ignorant men often find the door to heaven, and enter in, while the learned are looking for the latch.” Yes, a man may have clear eyes for worldly things; he may be very keen as for his insight into the problems of life, and yet the God of this world may have blinded his eyes.
What is even more remarkable, a man may have much scriptural knowledge; he may understand, in the letter, the things of the kingdom of God; he may be very orthodox in his beliefs, and may be able to give an answer to those who ask him what he believes, and why he believes; but still he may have no spiritual perception of the reality of these things. A person may know something of botany from books, and he may even understand the Linnaean system of classifying plants; but he may never, after all, have seen the primrose by the river’s bank, nor have gathered a single flower out of the garden. He is a poor botanist, is he not? He who has studied natural history in his own room, but has never seen a living animal, knows very little about the subject after all. We have many all around us, who can talk about heaven and hell, and sin and salvation, and Christ and the Holy Spirit, who nevertheless have never had one true perception of the meaning of any of these words. They see, but do not perceive; they hear, but do not understand; they are unbelievers, and the god of this world has blinded their minds.
Calvin – In what sense God is said to blind men, and to “give them up to a reprobate mind,” (Romans 1:28,) is evident from various passages of Scripture; that is, when he takes away the light of his Spirit, and gives a loose rein to the lust of men, so that no reasoning can restrain them. He likewise arms Satan with the efficiency of error, so that they who have refused to obey the truth do not guard against his snares, and are liable to be deceived by his impostures. What then can be left in us but the thickest darkness and gross ignorance, so that this tyrant, the father of lies and of darkness, ravages at his pleasure both within and without? for there will not be found in us any spark of light to dispel the clouds of error, but, impelled by a spirit of giddiness with which God strikes the reprobate, (2 Thessalonians 2:11,) we shall be driven about in a strange manner at the will of Satan.