Hadith 1348
Sayyida Aisha Siddiqa (may Allah be pleased with her) narrates: Fatimah bint Abu Hubaysh suffered from istihada (non-menstrual bleeding). The Prophet Muhammad (peace be upon him) said: The blood of menstruation is black and recognizable. When it is that, then refrain from prayer, and when it is of another color, then perform ablution and start offering prayer.