Asma bint Abi Bakr (may Allah be pleased with her) narrates: A woman asked the Prophet ﷺ, saying, "If menstrual blood gets on any of our clothes, what do you think she should do?" The Prophet ﷺ replied: "If menstrual blood gets on any of your clothes, she should rub it and wash it with water, then pour clean water over it, and then she may pray in it."
Hadith Referenceمسند الإمام الشافعي / كتاب الطهارة / 30