Hadith remembers God unceasingly. (Al-Ahzab 33: 21) The hadith literature is based on spoken reports in circulation after the death of Muhammad. Unlike the Qur'an, ahadith were not promptly written down during Muhammad's life or immediately after his death. Hadith were evaluated and gathered into large collections during the 8th and 9th centuries, generations after the death of Muhammad, after the end of the era of the "rightful" Rashidun Caliphate, over from where Muhammad lived. "Many thousands of times" more numerous than Quranic verse, ahadith have been described as resembling layers surrounding the “core” of the Islamic belief (the Quran). Well-known,
Criticism of Hadith hadith literature in general, especially in al‐Bukhārī, that were taken from haggadic literature. He then studied the ways of and how these narrations were transmitted to hadith literature. According to Taylor’s opinion, a large amount of the oral information, narrations, stories, and folkloric information entered in Islamic literature in general, and hadith literature, in particular, during the transcription of the Talmud and Mishnah and after the formation of hadiths via the Jews living in the Arabian Peninsula, as well as the church fathers and Christian community." Other scholars have different opinions on the same subject: Franz Buhl connects the ahadith