The Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, further explained: "The maximum duration for nifas is eighteen days. If the woman sees blood on the nineteenth day after giving birth, it is not considered nifas but istihadha (irregular bleeding). She should follow the rulings for istihadha, pray, and fast. However, there are authentic narrations indicating that the maximum duration for nifas is ten days, and this is the ruling I follow due to its clarity." He, Shaykh (Al-Mufid), added: "The principle here is that a woman’s obligations for prayer and fasting remain binding on her prior to nifas without any dispute. If nifas occurs, these obligations can only be lifted based on definitive evidence. There is no disagreement among Muslims that ten days of bleeding from nifas are exempted. Beyond this, there is a difference of opinion. Therefore, one should not act on an opinion that extends beyond ten days unless it provides irrefutable evidence. Any narrations suggesting a duration beyond ten days are solitary reports (khabar ahad) that do not provide definitive certainty, or they may have been conveyed for specific contexts or taqiyya (dissimulation). I will clarify their meanings, Allah سبحانه وتعالى willing. This evidence supports the view that the maximum duration of nifas is ten days."
Commentary #25