Webster's dictionary says The word blaspheme is broken down to it's meaningful parts thus : The first part that makes up the word is "blapsis", or to speak injurious, or with irreverence in it's content. The second part of the word and it's meaning is "phemi" meaning to speak out words impiously, and in this context directed to the Holy Spirit.
Webster's a great English dictionary. I think bible dictionary's are a better source for scripture.
Matt 12:
24 But when the Pharisees heard it, they said, This fellow doth not cast out devils, but by Beelzebub the prince of the devils.
(NOTE: The Pharisees claim Jesus healing power is done thru the prince of the devils/satan)
28 Jesus say's; if I cast out devils by the Spirit of God, then the kingdom of God is come unto you.
(NOTE: Jesus tells them its the Spirit of God, NOT SATAN, at work. It's right here they REJECTED God's Holy Spirit, their promised Messiah & temporarily lost out on His 1000 yr kingdom reign)
31 Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men.
(NOTE: REJECTING the work of the Holy Spirit equates to rejecting God. Rejecting God is the unpardonable sin.)
Gen chap 24:
Abraham (shadow of the Father) sends his best servant (shadow of the Holy Spirit) to find a bride for Isaac (shadow of Christ).
Gen 24:58: And they called Rebekah, and said unto her, Wilt thou go with this man? And she said, I will go.
(NOTE: Key point here - Rebekah has a choice - and agrees/says YES to marry Isaac)
Jn 12:32 Jesus said; if I be lifted up from the earth, will draw "all" men unto me.
(NOTE: The Father has sent the Promise/Holy Spirit to draw/offer redemption ALL to who will say YES to the Son!)
Tit 2:11 For the grace of God that bringeth salvation hath appeared to all men,
(NOTE: Jesus is the grace of God that brings salvation. Except or Reject His offer)
Jn 3:18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
(NOTE: Anyone that places their belief in Christ's sin payment & resurrection, WILL NOT be CONDEMNED. Anyone that REJECTS & remains in UNBELIEF is & will be CONDEMNED)
"REJECTION/ UNBELIEF" at life's end (ALL will be drawn) is the only UNPARDONABLE sin.