Hartwig Hirschfeld doubted the authenticity of the verse 33:40 and claimed it to be of late origin.
Yohanan Friedmann states that Hirschfeld's arguments "that the title
khatam an-nabiyyin is unusual, that it only appears once in the Qur'an, that the word
khatam is not Arabic…do not seem valid arguments against the authenticity of the verse."
Josef Horovitz suggested two possible interpretations of
khatam an-nabiyyin: the last prophet or the one who confirms the authenticity of the previous prophets. Heinrich Speyer agreed with Horovitz. The first modern academic to have studied in detail the history of the doctrine of finality of prophethood is Yohanan Friedmann. In his seminal article,
Finality of Prophethood in Sunni Islam (1986), he concluded that although the notion of finality of prophethood "eventually acquired an undisputed and central place in the religious thought of Islam," it was contested during the first century AH. However, in a more recent paper he states, "Most Muslims at the time no doubt understood it to mean that he was to be the last prophet and Islam was the final religion, as Muslims have commonly understood it ever since."
Carl W. Ernst considers the phrase to mean that Muhammad's "imprint on history is as final as a
wax seal on a letter." David Powers, also making use of Friedmann's research, believes that the early Muslim community was divided over the meaning of the expression, with some understanding it to mean he fulfilled or confirmed the earlier Christian and Jewish revelations, while others understood it as signifying that Muhammad brought the office of prophethood to a close. He suggests that the Qur'anic text underwent a series of secondary omissions and additions which were designed to adapt the text to the dogma of finality of prophethood, and that the idea of finality only became the prevailing interpretation (alongside the notion of confirmation or fulfilment) by the end of the 1st century AH / 7th century. In a review of Powers' book,
Gerald Hawting goes further, suggesting that the development of the doctrine was not complete before the 3rd century AH / 9th century. Madelung comments that Power's argument, that verses 36–40 are a later addition dating from the generation after Muhammad's death, is "hardly sustainable."
Uri Rubin holds that the finality of prophethood is a Qur'anic idea, not a post-Qur'anic one, and that the expression
khatam an-nabiyyin implies both finality of prophethood and confirmation. In response to Powers and other modern scholars sceptical of the early origin of the doctrine, Rubin concludes from his study "that, at least as far as Sura 33 is concerned, the consonantal structure of the Qur'anic text has not been tampered with, and that the idea of finality of prophethood is well-represented in the text, as well as in the earliest available extra-Quranic materials." Rubin reexamines the early extra-Qur'anic texts cited by Friedmann and other modern scholars, and concludes that rather than indicating that the notion of finality of prophethood is late, the texts confirm the early origin of the belief. He concludes that "there is no compelling reason to assume that the Muslims of the first Islamic century originally understood the Qur'anic
khatam an-nabiyyin in the sense of confirmation alone, without that of finality." == Official mandates ==