I say, and with God's success: It is not obligatory, but it is recommended to perform the ghusl (ritual washing) for him; based on the case of fainting; as narrated by Muslim in his Sahih from Ubaydullah ibn Abdullah who said: "I entered upon Aisha and said to her: 'Will you not tell me about the illness of the Messenger of God (peace be upon him)?' She said: 'Yes, the Prophet (peace be upon him) became ill and said: 'Did the people pray?' We said: 'No, they are waiting for you, O Messenger of God.' He said: 'Put water for me in the basin,' and we did so, and he performed ghusl, then he went to lean but fainted, then he regained consciousness and said: 'Did the people pray?' We said: 'No, they are waiting for you, O Messenger of God.' He said: 'Put water for me in the basin,' and we did so, and he performed ghusl ...' And God knows best.