From Sahih Muslim (Hadith 675):
Asma (daughter of Abu Bakr) reported:A woman came to the Messenger of Allah (ﷺ) and said: What should one do if the blood of menses smears the garment of one amongst us? He (the Holy Prophet) replied: She should scrape it, then rub it with water, then pour water over it and then offer prayer in it
Reference: Muslim 675