It was narrated from 'Urwah that Fatimah bint Abi Hubaish narrated that she came to the Messenger of Allah (ﷺ) and complained to him about bleeding. The Messenger of Allah (ﷺ) said to her:
That is a vein, so when your period comes, do not pray, and when your period is over, purify yourself and pray in between one period and the next. This is evidence that Al-Aqra' is menstruation. Abu 'Abdur-Rahman said: Hisham bin 'Urwah reported this Hadith from 'Urwah, and he did not mention what Al-Mundhir mentioned in it.