Narrated Umm Salamah (RAA):

During the lifetime of the Prophet (Peace be upon him) the women having bleeding after delivery (postnatal or puerperal blood) would refrain (from prayer) for forty days. [Reported by Al-Khamsa except An-Nasa’i, and the version is that of Abu Da’ud].

وَعَنْ أُمِّ سَلَمَةَ رَضِيَ اَللَّهُ عَنْهَا قَالَتْ: { كَانَتِ اَلنُّفَسَاءُ تَقْعُدُ فِي عَهْدِ رَسُولِ اَللَّهِ ‏- صلى الله عليه وسلم ‏-بَعْدَ نِفَاسِهَا أَرْبَعِينَ } رَوَاهُ اَلْخَمْسَةُ إِلَّا النَّسَائِيَّ, وَاللَّفْظُ لِأَبِي دَاوُد َ [1]‏ .‏