ENOfficial
Rafi' b. Khadij reported God’s Messenger as saying, “Observe Morning Prayer at dawn, for it is the practice most productive of reward.” Tirmidhi, Abu Dawud and Darimi transmitted it, but Nasa’i does not have “for it is the practice most productive of reward.”
Source: sunnah.com
Other translations
Arabic
وَعَنْ رَافِعِ بْنِ خَدِيجٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَسْفِرُوا بِالْفَجْرِ فَإِنَّهُ أَعْظَمُ لِلْأَجْرِ» . رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُدَ وَالدَّارِمِيُّ وَلَيْسَ عِنْدَ النَّسَائِيِّ: «فَإِنَّهُ أَعْظَمُ لِلْأَجْرِ»
sunnah.com