حَدَّثَنَا عَمْرُو بْنُ عَوْنٍ، أَخْبَرَنَا خَالِدٌ، عَنْ دَاوُدَ بْنِ أَبِي هِنْدٍ، عَنْ أَبِي حَرْبِ بْنِ أَبِي الأَسْوَدِ، عَنْ عَبْدِ اللَّهِ بْنِ فَضَالَةَ، عَنْ أَبِيهِ، قَالَ عَلَّمَنِي رَسُولُ اللَّهِ صلى الله عليه وسلم فَكَانَ فِيمَا عَلَّمَنِي ‏"‏ وَحَافِظْ عَلَى الصَّلَوَاتِ الْخَمْسِ ‏"‏ ‏.‏ قَالَ قُلْتُ إِنَّ هَذِهِ سَاعَاتٌ لِي فِيهَا أَشْغَالٌ فَمُرْنِي بِأَمْرٍ جَامِعٍ إِذَا أَنَا فَعَلْتُهُ أَجْزَأَ عَنِّي فَقَالَ ‏"‏ حَافِظْ عَلَى الْعَصْرَيْنِ ‏"‏ ‏.‏ وَمَا كَانَتْ مِنْ لُغَتِنَا فَقُلْتُ وَمَا الْعَصْرَانِ فَقَالَ ‏"‏ صَلاَةٌ قَبْلَ طُلُوعِ الشَّمْسِ وَصَلاَةٌ قَبْلَ غُرُوبِهَا ‏"‏ ‏.‏

Narrated Fudalah: The Messenger of Allah (PBUH) 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). Translation Not Available

Book Ref: Sunan Abi Dawud Book 2 Hadith 428
Web Ref:  Sunan Abi Dawud Book 2 Hadith 428