In his early position he held that she does not depart. Then I heard Ibn Abbas say, "The Messenger of Allah ﷺ granted them a concession."
حدثنا عفان حدثنا وهيب حدثنا عبد الله بن طاوس عن أبيه أنه
في أول أمره إنها لا تنفر قال ثم سمعت ابن عباس يقول رخص رسول الله ﷺ لهن
Its isnad is sahih, but its text is summarized and unclear. It appears that it concerns the concession given to women and the weak to depart from Muzdalifa at night. If that is indeed the case, then its meaning has already been conveyed more clearly than this at 4892, but it does not state that Ibn Umar used to forbid that and then retracted the prohibition. See Bukhari 3:420, Muslim 1:366, Bayhaqi 5:123, and Muwatta 1:250.It is also possible that this concerns the matter of a woman who begins menstruating after the tawaf al-ifadah. Tirmidhi narrated at 2:114, through the route of Abdullah, from Nafi, from Ibn Umar, who said, "Whoever performs hajj to the House, let his final engagement be with the House, except in the case of menstruation, for the Messenger of Allah granted women a concession regarding it." ﷺTirmidhi said, The hadith of Ibn Umar is hasan sahih. His commentator said, Nasai also narrated it, and Hakim graded it sahih.