The Book of Mosques and Places of Prayer
وَحَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ الْحَنْظَلِيُّ، أَخْبَرَنَا شُعَيْبُ بْنُ إِسْحَاقَ الدِّمَشْقِيُّ، حَدَّثَنَا الأَوْزَاعِيُّ، حَدَّثَنِي أَبُو النَّجَاشِيِّ، حَدَّثَنِي رَافِعُ بْنُ خَدِيجٍ، قَالَ كُنَّا نُصَلِّي الْمَغْرِبَ . بِنَحْوِهِ .A hadith like this, i. e." We used to observe evening prayer...." so on and so forth, has been narrated by Rafi' b. Khadij by another chain of transmitters
From Sahih Muslim, whose reports the scholars accept as authentic.