There is no Arabic word for blasphemy. Is that not interesting? English translators in their interpretative translations have translated the Arabic word kufr as blasphemy in several verses. There are twenty three verses in the Quran that contain the word blaspheme or its grammatical variants in Yusuf Ali’s translation of the Quran. These are 2:88, 102, 3:55, 4:155, 5:17, 64, 68, 72, 73, 103, 6:19, 8:35, 9:74, 10:70, 11:9, 14:28, 21:36, 21:112, 39:8, 39:32, 40:42, 43:15, 33. None of them speak about meting out punishment to the blasphemers by the ruler or by man. Verse 9:74 is about a ‘Muslim’ blasphemer a translation of which by Yusuf Ali is reproduced below. It speaks about Allah punishing them with a grievous penalty in this life and in the hereafter. By implication, the verse rules out punishment by man. Any law that seeks to punish a blasphemer is not in accordance with the Quran and goes against the letter and spirit of the Quran.
9: 74. They swear by Allah that they said nothing (evil), but indeed they uttered blasphemy, and they did it after accepting Islam; and they meditated a plot which they were unable to carry out: this revenge of theirs was (their) only return for the bounty with which Allah and His Messenger had enriched them! If they repent, it will be best for them; but if they turn back (to their evil ways), Allah will punish them with a grievous penalty in this life and in the Hereafter: They shall have none on earth to protect or help them.
Verse 43:33 (a translation of which by Yusuf Ali is reproduced below), speaks about blasphemers and says that, were it not for making blaspheming very attractive and presumably making belief extremely unattractive in comparison, God would have granted immense wealth to every blasphemer.