Mukhtasar Muslim (Abridged) 189 — Washing menstrual blood from clothes

Lady Asma bint Abi Bakr (may Allah be pleased with both of them) says that a woman came to the Messenger of Allah (peace and blessings be upon him) and asked, "If menstrual blood gets on any of our clothes, what should she do?" The Prophet (peace and blessings be upon him) said, "First, she should scrape it off, then pour water over it, rub it, and wash it. After that, she may pray in the same garment."