.... It seems that the stone-the-adulterers commandment has long been the subject of theological controversy because although mandated by traditional religious law, or shari’a, it does not appear in the Quran. Instead, the Quran mentions the much less severe punishments of flogging or perhaps confinement.
Some fornicators actually get into such things, maybe even in combination. Presumably a death sentence would have been important enough to merit inclusion in the revelation. Why didn’t Allah mention it before? According to another hadith, He did.
Muhammad had written down the revealed verse on a piece of paper and placed it under his bed for safekeeping. One day while Muhammad had taken ill and the household was preoccupied with nursing him, a goat wandered in and ate it. [Committee for Skeptical Inquiry] Read more