Adhab al-qabr is recorded here as contested because it was a genuine flashpoint in early Islamic theology, not merely a detail later generations took for granted. The Mu'tazila, the rationalist school that shaped much of ninth century Islamic theological debate, included figures who denied or reinterpreted the punishment of the grave, arguing that a body decomposing in the earth could not coherently be said to suffer in the way the hadith described, and preferring to read the relevant traditions figuratively or to set them aside where they conflicted with reasoned argument about the nature of body and soul.
Traditionalist scholars, and later the Ash'ari school that came to dominate Sunni orthodoxy, affirmed the punishment as literally true on the strength of hadith transmission, treating it as one of the unseen matters faith requires accepting on report rather than deriving from reason. The dispute mirrors a wider fault line in classical Islamic theology between traditions that gave hadith near scriptural authority on matters of the unseen and traditions, chiefly Mu'tazili, that subjected even well attested hadith to a filter of rational plausibility. Mainstream Sunni and Shia belief today follows the traditionalist affirmation, with adhab al-qabr taught as an article of faith.