 Hadith are also regarded by Muslims as important tools for understanding things mentioned in the Quran but not explained, a source for "tafsir" (commentaries written on the Quran).Some important elements, which are today taken to be a long-held part of Islamic practice and belief are not mentioned in the Quran, but are reported in hadiths.Therefore, Muslims usually maintain that hadiths are a necessary requirement for the true and proper practice of Islam, as it gives Muslims the nuanced details of Islamic practice and belief in areas where the Quran is silent.