- He has purified his inner self from the filth of shirk (associating partners with Allah), so it is only fitting that he purify his outward self by performing ghusl.
Some scholars have said that ghusl is not obligatory on this account (1). They argued that no general instruction has been reported from the Prophet, peace and blessings be upon him, such as, “Whoever embraces Islam should perform ghusl,” as he said, “Whoever among you comes to the Friday prayer should perform ghusl.” (2) So many of the Companions embraced Islam, yet it has not been transmitted that he, peace and blessings be upon him, instructed them to perform ghusl or said, “Whoever embraces Islam should perform ghusl.” Had it been obligatory, it would have been widely known, owing to people’s need for it.
We may say, however, that the first view—that ghusl is obligatory—is stronger. For when the Prophet, peace and blessings be upon him, gives a ruling to one member of the Ummah, and there is no intelligible reason for singling him out, then this is an instruction for the entire Ummah, since there is no reason to single him out. Moreover, his instructing one person does not mean that he did not instruct others likewise.
As for the fact that it has not been reported of every individual Companion that he performed ghusl after embracing Islam, we say: the absence of a report is not a report of absence. The basic principle is to act upon what the Prophet, peace and blessings be upon him, commanded, and it is not necessary for the practice of every individual to be transmitted.