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.

أَخْبَرَنَا 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 ‏.‏