They have not known nor understood: for he has shut their eyes, that they cannot see; and their hearts, that they cannot understand.
have not
Isaiah 44:9,20 They that make a graven image are all of them vanity; and their delectable things shall not profit; and they are their own witnesses; they see not, nor know; that they may be ashamed…
Isaiah 45:20 Assemble yourselves and come; draw near together, ye that are escaped of the nations: they have no knowledge that set up the wood of their graven image, and pray unto a god that cannot save.
Isaiah 46:7,8 They bear him upon the shoulder, they carry him, and set him in his place, and he standeth; from his place shall he not remove: yea, one shall cry unto him, yet can he not answer, nor save him out of his trouble…
for he hath
Isaiah 6:10 Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they see with their eyes, and hear with their ears, and understand with their heart, and convert, and be healed.
Isaiah 29:10 For the LORD hath poured out upon you the spirit of deep sleep, and hath closed your eyes: the prophets and your rulers, the seers hath he covered.
Psalm 81:12 So I gave them up unto their own hearts' lust: and they walked in their own counsels.
shut.
Isaiah 56:11 Yea, they are greedy dogs which can never have enough, and they are shepherds that cannot understand: they all look to their own way, every one for his gain, from his quarter.
Psalm 92:6 A brutish man knoweth not; neither doth a fool understand this.
Proverbs 2:5-9 Then shalt thou understand the fear of the LORD, and find the knowledge of God…
for He has shut their eyes so they cannot see
This part of the verse suggests divine judgment, where God allows the people's hearts to harden as a consequence of their persistent rebellion and idolatry. This is reminiscent of Pharaoh's hardened heart in Exodus, where God permits a natural progression of stubbornness as a form of judgment. It also connects to the New Testament, where Jesus speaks in parables so that those who are spiritually blind will not understand (Matthew 13:13-15).
and closed their minds so they cannot understand
The closing of minds signifies a deeper spiritual condition where understanding is blocked. This is not merely an intellectual deficiency but a spiritual one, where the truth of God is veiled. Paul speaks of a similar condition in 2 Corinthians 4:4, where the god of this age has blinded the minds of unbelievers. This closing of minds serves as a warning and a call to repentance, emphasizing the need for divine intervention to open hearts and minds to the truth.
• Idolatrous people “do not comprehend” because they have chosen substitutes for the living God (Isaiah 44:9-17).
• Romans 1:21-22 echoes this: “Although they knew God, they neither glorified Him as God…their thinking became futile.”
• Psalm 135:15-18 shows the futility of idols and the dullness that follows worshiping them.
• The verse states a present reality—spiritual dullness is already at work before the divine judgment described next.
• “Discern” points to moral and spiritual perception—the ability to tell right from wrong, truth from error (Hebrews 5:14).
• 1 Kings 18:21 highlights this failure when Israel wavers between Baal and the LORD.
• Without discernment, people accept lies, just as 2 Thessalonians 2:10 says they “refused the love of the truth.”
• God’s action is judicial: He confirms a rebellious choice (John 12:39-40 quoting Isaiah).
• Deuteronomy 29:4 shows the same principle: “Yet to this day the LORD has not given you a heart to understand, eyes to see, or ears to hear.”
• This hardening is not arbitrary; it follows persistent unbelief (Proverbs 29:1).
• Spiritual blindness prevents perceiving God’s glory in Christ (2 Corinthians 4:4).
• Matthew 13:13-15 describes hearing and seeing without grasping, fulfilling Isaiah’s pattern.
• The phrase underscores total inability apart from divine intervention.
• “Minds” (literally “hearts”) refer to the seat of will and affection.
• Ephesians 4:17-19 portrays Gentiles “darkened in their understanding…because of the hardness of their hearts.”
• God’s closing of the heart is both consequence and judgment of persistent idolatry.
• Understanding is the final, comprehensive grasp of truth. Without it, repentance and salvation do not occur (Acts 28:26-27).
• Yet Scripture offers hope: the same Lord who closes can also open hearts, as with Lydia in Acts 16:14 and with Israel in the future (Romans 11:25-27).
Isaiah 44:18 exposes the tragedy of idolatry: self-chosen blindness confirmed by God’s judicial hardening. Persisting in false worship deadens comprehension, discernment, sight, and understanding. God’s closing of eyes and minds is righteous judgment on willful rejection, but His grace can still break through to those who turn to Him.
(18) He hath shut their eyes.--Better, their eyes are smeared over. The state described is the judicial blindness of Romans 1:20-25. It will be remembered that blindness thus inflicted was one of the tortures of Eastern cruelty.Verse 18. - They have not known nor understood. The cause of all this folly is a Minding of the understanding, divinely caused in the way of punishment, on account of their having wilfully closed their eyes to the truth. Because they "did not like to retain God in their knowledge, God gave them up to a reprobate (or, undistinguishing) mind" (Romans 1:28; comp. Isaiah 29:10). He hath shut; or, One hath shut. But the reference is in either case to God. The word translated "shut" means literally "plastered" or "smeared."