It is narrated from Hazrat Hamnah bint Jahsh (may Allah be pleased with her) that once I presented myself before the Prophet (peace and blessings be upon him) and said that I have very severe and continuous menstrual bleeding. The Prophet (peace and blessings be upon him) said: "Use a cloth." I said that it is more severe than that (it does not stop with a cloth), and I am flowing like a stream. The Prophet (peace and blessings be upon him) said: "In that case, count six or seven days of each month as your menstrual period according to Allah's knowledge, then perform ghusl (ritual bath) and for the next twenty-three or twenty-four days, offer prayers and keep fasts. And keep this arrangement: perform ghusl once for the Fajr prayer, then delay Zuhr and bring Asr forward and perform ghusl once to offer both these prayers together, then delay Maghrib and bring Isha forward and perform ghusl once to offer both these prayers together. I prefer this method over the other method."