Sunan an-Nasa'i 506
سنن النسائي#506Sahihأَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ مَالِكٍ، قَالَ حَدَّثَنِي الزُّهْرِيُّ، وَإِسْحَاقُ بْنُ عَبْدِ اللَّهِ، عَنْ أَنَسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُصَلِّي الْعَصْرَ ثُمَّ يَذْهَبُ الذَّاهِبُ إِلَى قُبَاءٍ فَقَالَ أَحَدُهُمَا فَيَأْتِيهِمْ وَهُمْ يُصَلُّونَ وَقَالَ الآخَرُ وَالشَّمْسُ مُرْتَفِعَةٌ .
It was narrated from Anas:"The Messenger of Allah (ﷺ) used to pray 'Asr, then a person could go to Quba'." One of them [1] said: "And he would come to them when they were prayed." The other said: "And the sub was still high." [1] Both Az-Zuhri and Ishaq bin 'Abdullah narrated it from Anas, so the reference is about them
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 6:13