I say, and with God's success: it is blood, even if it is a ruling issued from the womb of a mature woman who has no illness or pregnancy and has not reached menopause. This definition is found in Al-Wiqayah p. 120, Al-Maraqi p. 138, Al-Hadiyah Al-Ala'iyah p. 43, Dhakhr Al-Mutahhilin p. 32, and others. And God knows best.