Regarding the fifteen days, where did we take this specific limit from?

Question : Fifteen days, where did we take this limit from?

Answer : No, there is no fixed limit, but if it exceeds fifteen days, it requires that most of the time be blood. This is as the woman said to the Messenger (peace and blessings be upon him): "I have severe, heavy irregular bleeding that prevents me from praying." So he told her to sit for the usual period of most women.