Musnad Abu Ya'la al-Mawsili 149:54

'Abd al-'Aziz ibn Abi Salamah al-'Umari narrated to us, Ibrahim ibn Sa'd narrated to me, from al-Zuhri, from 'Amrah, from 'Aishah, who said: Umm Habibah bint Jahsh came—and she had been experiencing istihadah (prolonged non-menstrual bleeding) for seven years—to the Messenger of Allah (may Allah bless him and grant him peace). She complained of that to him and sought his religious ruling regarding it. He said: "Indeed, this is not the menstruation, but rather this is a vein. So perform ghusl (ritual bath), then pray." She used to perform ghusl for every prayer, and she would sit in a washbasin, and the redness of the blood would rise upon the water, then she would pray.