Matthew 12:31-32 (Larger context: 12:22-37)

31 "Therefore I say to you, any sin and blasphemy shall be forgiven men, but blasphemy against the Spirit shall not be forgiven.

32 "And whoever shall speak a word against the Son of Man, it shall be forgiven him; but whoever shall speak against the Holy Spirit, it shall not be forgiven him, either in this age, or in the {age} to come.

Mark 3:28-30 (Larger context: 3:20-30)

28 "Truly I say to you, all sins shall be forgiven the sons of men, and whatever blasphemies they utter;

29 but whoever blasphemes against the Holy Spirit never has forgiveness, but is guilty of an eternal sin"--

30 because they were saying, "He has an unclean spirit."

Luke 12:10

10 "And everyone who will speak a word against the Son of Man, it shall be forgiven him; but he who blasphemes against the Holy Spirit, it shall not be forgiven him.