Israel's national sin is unforgiveable
They rejected the Kingdom
And whosoever speaketh a word against the Son of Man, it shall be forgiven him: but whosoever speaks against the Holy Ghost, it shall not be forgiven him, neither in this world, or in the world to come.and crucified the King
Then answered all the people, and said, His blood be on us, and on our children.
This sin is not to be forgiven in the world (this world) ( age, or dimension ) within which the crime was committed
nor in the age or dimension to come
but God's unending mercy endures through all dimensions
For the LORD is good; his mercy is everlasting; and his truth endureth to all generations.
and in reply to the Son's plea and as predicted in prophecy there is an age when Israel will stand pardoned for the unpardonable
(Lev 26:40)If they shall confess their iniquity, and the iniquity of their fathers, with their trespass which they trespassed against me, and that also they have walked contrary unto me; ..................
(Lev 26:42)Then will I remember my covenant with Jacob, and also my covenant with Isaac, and also my covenant with Abraham will I remember; and I will remember the land.
This confessed sin is expressed as a singular crime although it was twofold in both rejecting King and Kingdom.
We read of the singular committed and confessed and forgiven crime again in Isaiah 40:2
(Isa 40:2)Speak ye comfortably to Jerusalem, and cry unto her, that her warfare is accomplished, that her iniquity is pardoned: for she hath received of the LORD'S hand double for all her sins.
And again in Jeremiah
(Jer )Only acknowledge thine iniquity, that thou hast transgressed against the LORD thy God, and hast scattered thy ways to the strangers under every green tree, and ye have not obeyed my voice, saith the LORD.
And again in Hosea
I will go and return to my place, till they acknowledge their offence, and seek my face: in their affliction they will seek me early.
In Hosea their confession is prompted by great tribulation and results in the return of the Lord.
Israel commits an unspeakable and unpardonable crime and only after suffering tribulation becomes willing to admit to the transgression, and the merciful rejected King forgives and receives them
How much tribulation must one endure before the old sin nature gives up and confesses unpardonable crimes?
And will the pardoned criminal find the forgiving face of mercy at his confession?