A punishment which is not in the Quran and contrary to the Quran: Rajm (Stoning)
The stoning, which means the punishment of killing adulterers by stoning, is in the Old Testament (Deuteronomy 22:22). There is no such severe punishment in the Quran (an-Nisa  15; an-Nur  2).
According to the tradition, rajm is a part of Islam, but rajm is contrary to these Quran verses:
Note: The allegation that the verses in the Quran are for single people, but married people should be stoned, is invalid. Because an-Nur  2, doesn’t make any difference between single and married people. Even the word single is not used in this verse. An-Nur  6, is about the adultery of married people [Spouses اَزْوَاجَهُمْ – Azwajahum].