I say, and with God's success: It is obligatory to stop; due to His saying: {And do not approach them until they are pure} Al-Baqarah: 222, according to the reading with emphasis, for He, Glory be to Him, prohibited approaching them until they have washed, and if it were not obligatory, He would not have prohibited it. And from Aisha, may Allah be pleased with her: "Fatimah bint Abi Hubaysh was experiencing irregular bleeding, so she asked the Prophet, peace be upon him, and he said: That is a vein, and it is not menstruation. When menstruation comes, then stop praying, and when it goes away, wash and pray," in Sahih al-Bukhari 1: 122, and Al-Mustadrak 1: 281. And from Mu'adh, may Allah be pleased with him, he said: The Prophet, peace be upon him, said: "If the postpartum woman has seven days, then sees purity, she should wash and pray," in Al-Mustadrak 1: 284. And Al-Tahanawi said in I'la al-Sunan 1: 203: Its chain of narration is authentic according to the principles of Al-Kanz mentioned in his sermon. See: Al-Ikhtiyar 1: 20, and Sharh al-Wiqayah p. 95, and Allah knows best.