it's never been the election (faithful, saved) who was given the "spirit of slumber"
Deuteronomy 29:4
But to this day the LORD has not given you a mind that understands or eyes that see or ears that hear.
Isaiah 6:9
He said, "Go and tell this people: "'Be ever hearing, but never understanding; be ever seeing, but never perceiving.'
Jeremiah 5:21
Hear this, you foolish and senseless people, who have eyes but do not see, who have ears but do not hear:
Ezekiel 12:2
"Son of man, you are living among a rebellious people. They have eyes to see but do not see and ears to hear but do not hear, for they are a rebellious people.
Mark 4:12
so that, "'they may be ever seeing but never perceiving, and ever hearing but never understanding; otherwise they might turn and be forgiven!'"
Luke 8:10
He said, "The knowledge of the secrets of the kingdom of God has been given to you, but to others I speak in parables, so that, "'though seeing, they may not see; though hearing, they may not understand.'
John 12:40
"He has blinded their eyes and deadened their hearts, so they can neither see with their eyes, nor understand with their hearts, nor turn--and I would heal them."
Acts 28:26
"'Go to this people and say, "You will be ever hearing but never understanding; you will be ever seeing but never perceiving."
Acts 28:27
For this people's heart has become calloused; they hardly hear with their ears, and they have closed their eyes. Otherwise they might see with their eyes, hear with their ears, understand with their hearts and turn, and I would heal them.'
Romans 10:16
But not all the Israelites accepted the good news. For Isaiah says, "Lord, who has believed our message?"
Romans 11:8
as it is written: "God gave them a spirit of stupor, eyes so that they could not see and ears so that they could not hear, to this very day."
Matthew 13:14
In them is fulfilled the prophecy of Isaiah: "'You will be ever hearing but never understanding; you will be ever seeing but never perceiving.
And in them is fulfilled-rather, "is fulfilling," or "is receiving its fulfilment."
the prophecy of Esaias, which saith-(Isa 6:9, 10-here quoted according to the Septuagint).
By hearing ye shall hear, and shall not understand, &c.-They were thus judicially sealed up under the darkness and obduracy which they deliberately preferred to the light and healing which Jesus brought nigh to them.
JFBBC
Waxed gross - Literally, "has become fat." This language is commonly applied to "the body," but is also used to denote one who is stupid and foolish in mind. Here it means that the people were so sensual and corrupt that they did not see or understand the pure spiritual principles of the gospel.
Lest they should see ... - Lest they should see their lost condition as sinners, and turn and live. The reason given here why they did not hear and understand the gospel is, that their "heart" was "wrong." They "would" not attend to the things that belonged to their peace.
Barnes
13:14 Hearing ye will hear, but in nowise understand - That is, Ye will surely hear. All possible means will be given you: yet they will profit you nothing; because your heart is sensual, stupid, and insensible; your spiritual senses are shut up; yea, you have closed your eyes against the light; as being unwilling to understand the things of God, and afraid, not desirous that he should heal you. Isaiah 6:9; John 12:40; Acts 28:26.
Wesley
In them is fulfilled - Αναπληρουται, Is Again fulfilled: this proper meaning of the Greek word has been generally overlooked. The evangelist means, that as these words were fulfilled in the Jews, in the time of the Prophet Isaiah, so they are now again fulfilled in these their posterity, who exactly copy their fathers example. These awful words may be again fulfilled in us, if we take not warning by the things which these disobedient people have suffered.
Clarke
Is fulfilled (anaplhroutai). Aoristic present passive indicative. Here Jesus points out the fulfilment and not with Matthew's usual formula (ina or opw plwrhqh to rhqen (see John 1:22 ). The verb anaplhrow occurs nowhere else in the Gospels, but occurs in the Pauline Epistles. It means to fill up like a cup, to fill another's place ( 1 Corinthians 14:16 ), to fill up what is lacking ( Philippians 2:30 ). Here it means that the prophecy of Isaiah is fully satisfied in the conduct of the Pharisees and Jesus himself points it out. Note two ways of reproducing the Hebrew idiom (infinitive absolute), one by akoh the other by bleponte. Note also the strong negative ou mh with aorist subjunctive.
Robertsons
10 Then the disciples came up and asked Him, "Why do You speak to them in parables?" 11 He answered them, "Because the secrets does not mean "mysteries" in the Eng sense; it means what we can know only by divine revelation. of the kingdom of heaven have been given for you to know, but it has not been given to them. 12 For whoever has, [more] will be given to him, and he will have more than enough. But whoever does not have, even what he has will be taken away from him. 13 For this reason I speak to them in parables, because looking they do not see, and hearing they do not listen or understand. 14 Isaiah's prophecy is fulfilled in them, which says: You will listen and listen, yet never understand; and you will look and look, yet never perceive. 15 For this people's heart has grown callous; their ears are hard of hearing, and they have shut their eyes; otherwise they might see with their eyes and hear with their ears, understand with their hearts and turn back- and I would cure them. 16 "But your eyes are blessed because they do see, and your ears because they do hear!
Holman