Ja'far bin Muhammad said:
My father told me: 'We came to Jabir bin 'Abdullah and asked him about the Hajj of the Prophet (ﷺ). He narrated; The Messenger of Allah (ﷺ) set out when there were five (days) remaining in Dhul-Qa'dah, and we set out with him. When he came to Dhul-Hulaifah, Asma' bint 'Umais gave birth to Muhammad bin Abi Bakr. She sent word to the Messenger of Allah (ﷺ) asking what he should do. He said: 'Perform Ghusl, bind yourself with a cloth then begin (the Talbiyah for Ihram).'