The Book of Fasting
حَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ، عَنْ سُفْيَانَ، عَنْ سَالِمٍ أَبِي، النَّضْرِ بِهَذَا الإِسْنَادِ نَحْوَ حَدِيثِ ابْنِ عُيَيْنَةَ وَقَالَ عَنْ عُمَيْرٍ، مَوْلَى أُمِّ الْفَضْلِ .This hadith has been narrated by Abu Nadr on the authority of Umair, the freed slave of Umm al-Fadl, through the same chain of transmitters
From Sahih Muslim, whose reports the scholars accept as authentic.