So you do not believe the "rest" and "refreshing" is found in believing in the Word of God about their promised Messiah although it was the repeated "doctrine" of all the prophets (v. 9) and thus "precept upon precept, here a little and there a little (v. 10). You don't believe this promised rest preached by all the prophets was "the word of the Lord" that had been given unto them "precept upon precept, line upon line, here a littel, and there a little (v. 13).
You cannot see that in verse 14 Isaiah repeats the same promise AGAIN or the "word of the Lord" about their coming Messiah and beleiving on him versus a covenant of death by rejection of him?
Do you see how verses 11-12 are placed between verses 9-10 and verse 13 which all speak about the same thing?
9 ¶ Whom shall he teach knowledge? and whom shall he make to understand doctrine? them that are weaned from the milk, and drawn from the breasts.
10 For precept must be upon precept, precept upon precept; line upon line, line upon line; here a little, and there a little:
11 For with stammering lips and another tongue will he speak to this people.
12 To whom he said, This is the rest wherewith ye may cause the weary to rest; and this is the refreshing: yet they would not hear.
13 But the word of the LORD was unto them precept upon precept, precept upon precept; line upon line, line upon line; here a little, and there a little; that they might go, and fall backward, and be broken, and snared, and taken.
14 ¶ Wherefore hear the word of the LORD, ye scornful men, that rule this people which is in Jerusalem.
15 Because ye have said, We have made a covenant with death, and with hell are we at agreement; when the overflowing scourge shall pass through, it shall not come unto us: for we have made lies our refuge, and under falsehood have we hid ourselves:
16 Therefore thus saith the Lord GOD, Behold, I lay in Zion for a foundation a stone, a tried stone, a precious corner stone, a sure foundation: he that believeth shall not make haste.
This text says nothing about Pentecost. Nothing about the Promise of the Spirit. Only that tongues from other people will tell them the same thing that all the prophets had told them with one difference - HE HAS COME and that is precisely what Peter told them on the day of Pentecosts and it was tongues that confirmed this message and got their attention.
The problem is that you have made up your mind in spite of the facts and there is no basis to discuss it any more with you.