They have not known nor understood - They are stupid, ignorant, and blind. Nothing could more strikingly show their ignorance and stupidity than this idol worship.

He hath shut their eyes - God hath closed their eyes. Margin, 'Daubed.' The word used here, טה ṭah from טוה ṭûah denotes properly "to spread over"; to besmear; to plaster; as, e. g., a wall with mortar Leviticus 14:42; 1 Chronicles 29:4; Ezekiel 13:10; Ezekiel 22:28. Here it means to cover over the eyes so as to prevent vision; and hence, metaphorically, to make them stupid, ignorant, dull. It is attributed to God in accordance with the common statement of the Scriptures, that he does what he permits to be done (see the notes at Isaiah 6:9-10). It does not mean that God had done it by any physical, or direct agency, but that it had occurred under the administration of his Providence. It is also true that the Hebrew writers sometimes employ an active verb when the signification is passive, and when the main idea is, that anything was in fact done. Here the main point is not the agent by which this was done, but the fact that their eyes were blinded - and perhaps all the force of the verb טה ṭah used here would be expressed if it was rendered in an impersonal, or in a passive form, 'it is covered as to their eyes,' that is, their eyes are shut, without suggesting that it was done by God. So the Septuagint renders it, Ἀπημαυρώθησαν Apēmaurōthēsan - 'They are blind,' or involved in darkness.

So the Chaldee, מטמטמן meṭmeṭemân (also in the plural) - 'Their eyes are obscured' or blind. It cannot be proved from this text that God is, by direct agency, the author by whom it was done. It was not uncommon to shut up, or seal up the eyes for various purposes in the East, and unquestionably the prophet alludes to some such custom. 'It is one of the solemnities at a Jewish wedding at Aleppo, according to Dr. Russell, who mentions it as the most remarkable thing in their ceremonies at that time. It is done by fastening the eyelids together with a gum, and the bridegroom is the person, he says, if he remembered right, that opens the bride's eyes at the appointed time. It is also used as a punishment in those countries. So Sir Thomas Roe's chaplain, in his account of his voyages to East India, tells us of a son of the Great Mogul, whom he had seen, and with whom Sir Thomas had conversed, that had before that time been cast into prison by his father, where his eyes were sealed up, by something put before them, which might not be taken off for three years; after which time the seal was taken away, that he might with freedom enjoy the light, though not his liberty.' (Harmer's Obs. vol. iii., pp. 507, 508. Ed. Lond. 8vo, 1808.)

He hath shut their eyes "Their eyes are closed up" - The Septuagint, Chaldee, and Vulyate, for טח tach, read טחו tachu. See note on Isaiah 6:10.

They have not known nor understood,.... Who the true God is, nor the worship that is due to him alone; they do not know nor understand divine and spiritual things; nay, they have not the knowledge and understanding of men; they want common sense that can do and say such things as before mentioned, both idol makers and idol worshippers:

for he hath shut their eyes that they cannot see, and their heart that they cannot understand; either the devil, as some think, the god of this world, that blinds their eyes from seeing the folly of such gross idolatry, which he, deceiving them, leads them into; or rather God himself, who, because they like not to retain him in their knowledge, gives them up to a reprobate and injudicious mind, to believe a lie, and worship a false god; this he permits, orders, and overrules to some good ends and purposes: this is to be understood of the eyes of the understanding, which, as the word (i) signifies, are "daubed" and plastered over, that there is no opening of them, and seeing with them; which is the judicial blindness and hardness of heart, which God sometimes in righteous judgment gives up men unto; see Romans 1:28.

(i) "oblevit oculos eorum", Montanus; "obleverit", Cocceius; "quod sculptile oblinat", Piscator.

So irrational is idolatry; but yet, through self-hardening, they have fallen under the judgment of hardness of heart (Isaiah 6:9-10; Isaiah 19:3; Isaiah 29:10), and have been given up to a reprobate mind (Romans 1:28). "They perceive not, and do not understand: for their eyes are smeared over, so that they do not see; their hearts, so that they do not understand. And men take it not to heart, no perception and no understanding, that men should say, The half of it I have burned in the fire, and also baked bread upon the coals thereof; roasted flesh, and eaten: and ought I to make the rest of it an abomination, to fall down before the produce of a tree?" Instead of טח, Leviticus 14:42, the third person is written טח (from tâchach, Ges. 72, Anm. 8) in a circumstantial sense: their eyes are, as it were, smeared over with plaster. The expression אל־לב השׁיב or על־לב (Isaiah 46:8), literally to carry back into the heart, which we find as well as על־לב שׂים, to take to heart (Isaiah 42:25), answers exactly to the idea of reflection, here with reference to the immense contrast between a piece of wood and the Divine Being. The second and third לא in Isaiah 44:19 introduce substantive clauses, just as verbal clauses are introduced by ואין. לאמר is used in the same manner as in Isaiah 9:8 : "perception and insight showing themselves in their saying." On būl, see Job 40:20; the meaning "block" cannot be established: the talmudic būl, a lump or piece, which Ewald adduces, is the Greek βῶλος.

They have not known nor understood: {y} for he hath shut their eyes, that they cannot see; and their hearts, that they cannot understand.

(y) The prophet gives here an answer to all them who wonder how it is possible that any would be so blind as to commit such abomination, saying that God has blinded their eyes, and hardened their hearts.

44:18 Not known - This shews that they have not the understanding of a man. For he - God. Not as if God did make men wicked; he only permits them so to be, and orders, and over - rules their wickedness to his own glorious ends.

shut: Heb. daubed

18. he, &c.-God hath given them over to judicial blindness; not His direct physical, but His providential agency in administering His moral government, is meant (Isa 6:9, 10). "Shut," literally, "daubed," plastered up; it is an Eastern custom in some cases to seal up the eyes of offenders.

44:9-20 Image-making is described, to expose the folly of idolaters. Though a man had used part of a log for fuel, he fell down before an image made of the remainder, praying it to deliver him. Man greatly dishonours God, when he represents him after the image of man. Satan blinds the eyes of unbelievers, causing absurd reasonings in matters of religion. Whether men seek happiness in worldly things, or run into unbelief, superstition, or any false system, they feed on ashes. A heart deceived by pride, love of sin, and departure from God, turns men aside from his holy truth and worship. While the affections are depraved, a man holds fast the lie as his best treasure. Are our hearts set upon the wealth of the world and its pleasures? They will certainly prove a lie. If we trust to outward professions and doings, as if those would save us, we deceive ourselves. Self-suspicion is the first step towards self-deliverance. He that would deliver his soul, must question his conscience, Is there not a lie in my right hand?