or replace them with new ones, for Abū Dāwūd (356) and al-Bayhaqī (8/323) transmit—through ʿUthaym ibn Kathīr ibn Kulayb al-Ḥaḍramī, from his father, from his grandfather—that when the latter accepted Islam the Prophet ﷺ said to him: “Alqi ʿanka shaʿra al-kufr (cast off the hair of disbelief).” Al-Nawawī comments that the chain is not strong, because ʿUthaym is unknown and has not been declared reliable. Nevertheless, Abū Dāwūd recorded the report without grading it weak, and he stated that whenever he cites a ḥadīth without discrediting it, he deems it sound; hence, in his estimation this narration is ḥasan (fair).

Disagreement among the scholars
• Imāms Mālik and Aḥmad held that performing ghusl is obligatory when a person embraces Islam after disbelief, whether or not he had previously done something that would itself necessitate a bath. This is also the view of Abū Thawr and Ibn al-Mundhir. They adduce the present report, along with the narration in Aḥmad and al-Tirmidhī that “when Qays ibn ʿĀṣim accepted Islam, the Prophet ﷺ ordered him to bathe”; Shaykh al-Albānī judged that isnād authentic and understood the Prophet’s command as binding.
• Imām al-Shāfiʿī maintained that ghusl becomes obligatory only if, during his unbelief, the person had incurred a state that demands a bath.
• Imām Abū Ḥanīfah ruled that ghusl is never obligatory for the new Muslim.

Those who do not require it argue that Islam erases whatever preceded it, and that vast numbers embraced the faith; had the Prophet ﷺ ordered every convert to bathe, the practice would have reached us by tawātur (multiple-chain mass transmission). As for the report about Qays ibn ʿĀṣim, they interpret it as merely recommendatory. Al-Khaṭṭābī says this is the opinion held by most scholars.

Assessing the dispute
Al-Shāfiʿī’s view—that ghusl is compulsory only for the convert who, while still an unbeliever, had incurred major impurity—finds no supporting evidence, for there is no report that the Prophet ﷺ ever questioned new Muslims about such matters. Had that questioning been obligatory, he would certainly have asked them, and the sheer number of conversions in the presence of the Companions would have ensured that this detail reached us through multiple concurrent transmissions.

We are therefore left with two possibilities: a blanket obligation or a blanket recommendation; and the case of Thumamah ibn Uthāl