Jesus was God’s sign that would be spoken against
Isaiah boldly prophesied that the birth of the Messiah, Immanuel (God with us), would be a sign.
Isaiah 7v10 Moreover the LORD spake again unto Ahaz, saying, 11 Ask thee a sign of the LORD thy God; ask it either in the depth, or in the height above. 12 But Ahaz said, I will not ask, neither will I tempt the LORD. 13 And he said, Hear ye now, O house of David; Is it a small thing for you to weary men, but will ye weary my God also? 14 Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel. 15 Butter and honey shall he eat, that he may know to refuse the evil, and choose the good. 16 For before the child shall know to refuse the evil, and choose the good, the land that thou abhorrest shall be forsaken of both her kings.
Luke’s gospel records that Jesus himself would be a sign which would be spoken against, i.e., rejected. It is interesting to note when reading the gospel accounts that Jesus was rejected by the religious leaders. Although Jesus performed signs (miracles) of healing, raising the dead, walking on water, to name a few, he was actually the initial sign which would be rejected by the majority of Israel.
Luke 2v25
And, behold, there was a man in Jerusalem, whose name was Simeon; and the same man was just and devout, waiting for the consolation of Israel: and the Holy Ghost was upon him. 26 And it was revealed unto him by the Holy Ghost, that he should not see death, before he had seen the Lord’s Christ. 27 And he came by the Spirit into the temple: and when the parents brought in the child Jesus, to do for him after the custom of the law, 28 Then took he him up in his arms, and blessed God, and said, 29 Lord, now lettest thou thy servant depart in peace, according to thy word: 30 For mine eyes have seen thy salvation, 31 Which thou hast prepared before the face of all people; 32 A light to lighten the Gentiles, and the glory of thy people Israel. 33 And Joseph and his mother marvelled at those things which were spoken of him. 34 And Simeon blessed them, and said unto Mary his mother, Behold, this child is set for the fall and rising again of many in Israel; and for a sign which shall be spoken against; 35 (Yea, a sword shall pierce through thy own soul also,) that the thoughts of many hearts may be revealed.
Matthew 21v42 Jesus saith unto them, Did ye never read in the scriptures, The stone which the builders rejected, the same is become the head of the corner: this is the Lord’s doing, and it is marvellous in our eyes?
Tongues is God’s sign which is spoken against
Isaiah goes on to boldly prophesy about speaking in tongues and how this would be spoken against, rejected.
Isaiah 28v11 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.
Paul quotes from Isaiah and identifies tongues
Paul, here in 1 Corinthians, quoting from Isaiah 28, identifies tongues as a sign. Those who believe in Jesus perform signs (miracles), see Mark 16v17-18, just as Jesus did, John 14v12, but tongues, is the intial sign.
1 Corinthians 14v21 (quoting from Isaiah 28)
In the law it is written, With men of other tongues and other lips will I speak unto this people; and yet for all that will they not hear me, saith the Lord. 22 Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying serveth not for them that believe not, but for them which believe.
Isaiah 28v11-12 identifies tongues, rest and refreshing
Isaiah identies tongues with the rest and refreshing. Jesus spoke of rest.
Matthew 11v28 Come unto me, all ye that labour and are heavy laden, and I will give you rest. 29 Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls. 30 For my yoke is easy, and my burden is light.
Peter spoke of the refreshing when making a reference to receiving the Holy Spirit.
Acts 3v19 Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord;
The believer in Christ, because they have received the Holy Spirit, has entered into God’s rest.
Hebrews 4v3 For we which have believed do enter into rest, as he said, As I have sworn in my wrath, if they shall enter into my rest: although the works were finished from the foundation of the world.
Tongues is evidence of receiving the Holy Spirit
Acts 2v4 And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
Acts 10v44 While Peter yet spake these words, the Holy Ghost fell on all them which heard the word. 45 And they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost. 46 For they heard them speak with tongues, and magnify God. Then answered Peter, 47 Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?
Acts 19v6 And when Paul had laid his hands upon them, the Holy Ghost came on them; and they spake with tongues, and prophesied.
Jesus Christ - God's Answer 