´It was narrated from Jabir bin 'Abdullah, in the Hadith of Asma' bint 'Umair, when she gave birth in Dhul-Hulaifah, that the Messenger of Allah (ﷺ) said to Abu Bakr:` "Tell her to perform Ghusl and enter Ihram."
Hadith Referenceسنن نسائي / ذكر ما يوجب الغسل وما لا يوجبه / 215
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح مسلم