Ikrima reported,
The people of Medina asked Ibn Abbas 
about a woman who performed the tawaf and then began menstruating.He told them, "She may depart."They said, "We will not accept your view and abandon the view of Zayd."He replied, "When you return to Medina, ask around."So they returned to Medina and asked, and among those they questioned was Umm Sulaym, who related the hadith of Safiyyah.
Azami 5242
Sahihعن عكرمة
أن أهل المدينة سألوا ابن عباس رضي الله عنهما، عن امرأة طافت، ثم حاضت؟ قال لهم: تنفر. قالوا: لا نأخذ بقولك وندع قول زيد قال: إذا قدمتم المدينة فسلوا، فقدموا المدينة فسألوا، فكان فيمن سألوا أم سليم ( فذكرت حديث صفية).
Bukhari narrated it in the Hajj chapter (1758-1759) through the route of Ayub, from Ikrima, with the account as mentioned. Muslim also narrated it in the Hajj chapter (1328:381) through the route of Hasan bin Muslim, from Tawus, who said, "I was with Ibn Abbas when Zayd bin Thabit said, 'Do you give the ruling that a menstruating woman may leave before her last contact with the House is the farewell tawaf?' Ibn Abbas said to him, 'If that is not so, then ask so-and-so the Ansari woman whether the Messenger of Allah ﷺ commanded her to do that.' " He said, "Zayd bin Thabit then returned to Ibn Abbas laughing, saying, 'I see that you have indeed told the truth.'"It appears that the Ansari woman is Umm Salim, who is mentioned in Ikrima's narration as recorded by Bukhari. Indeed, Hafiz stated this definitively in Fath al-Bari (3/588). Umm Salim is the daughter of Milhan, and she is the mother of Anas bin Malik .As for Ibn Abbas's saying, "If that is not so," Ibn Athir said, "The origin of this expression is 'in' and 'ma,' where the nun was assimilated into the mim, and the 'ma' is redundant in wording, carrying no independent meaning. The Arabs pronounced the 'la' with a light imala. Its meaning is, 'If you do not do this, then let this be the case.'"