The Messenger of Allah ﷺ taught me and what he taught me is this: Observe the five prayers regularly. He said: I told (him): I have many works at these times; so give me a comprehensive advice which, if I follow, should be enough for me. He said: Observe the two afternoon prayers (al-asrayn). But the term al-asrayn (two afternoon prayers) was not used in our language. Hence I said: What is al-asrayn? He said: A prayer before the sunrise and a prayer before the sunset (i.e. the dawn and the afternoon prayers). (Using translation from Abū Dāʾūd 428)
عَلَّمَنِي رَسُولُ اللهِ ﷺ فَكَانَ فِيمَا عَلَّمَنِي أَنْ قَالَ «حَافِظْ عَلَى الصَّلَوَاتِ الْخَمْسِ» فَقُلْتُ إِنَّ هَذِهِ سَاعَاتٌ لِي فِيهَا أَشْغَالٌ فَمُرْنِي بِأَمْرٍ جَامِعٍ إِذَا أَنَا فَعَلْتُهُ أَجْزَأَ عَنِّي قَالَ «حَافِظْ عَلَى الْعَصْرَيْنِ» قُلْتُ وَمَا الْعَصْرَانِ؟ قَالَ «صَلَوَاتٌ قَبْلَ طُلُوعِ الشَّمْسِ وَصَلَاةٌ قَبْلَ غُرُوبِهَا»