Purification (Kitab Al-Taharah)
Dawud :: Book 1 : Hadith 305
Narrated Umm Habibah daughter of Jahsh:
Ikrimah said: Umm Habibah daughter of Jahsh had a prolonged flow of blood. The Prophet (peace_be_upon_him) commanded her to refrain (from prayer) during her menstrual period; then she should wash and pray, if she sees anything (which renders ablution void) she should perform ablution and pray.