It was narrated that 'Uqbah bin 'Amir said: "The Prophet (ﷺ) was given a gray mule which he rode, and 'Uqbah led it. The Messenger of Allah (ﷺ) said to 'Uqbah: 'Recite.' He said: 'What should I recite, O Messenger of Allah?' He said: 'Recite: 'Say: I seek refuge with (Allah) the Lord of the daybreak, from the evil of what He has created.' And he repeated it until I had learned it."
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنِي عَمْرُو بْنُ عُثْمَانَ، قَالَ حَدَّثَنَا بَقِيَّةُ، قَالَ حَدَّثَنَا بَحِيرُ بْنُ سَعْدٍ، عَنْ خَالِدِ بْنِ مَعْدَانَ، عَنْ جُبَيْرِ بْنِ نُفَيْرٍ، عَنْ عُقْبَةَ بْنِ عَامِرٍ، قَالَ أُهْدِيَتْ لِلنَّبِيِّ صلى الله عليه وسلم بَغْلَةٌ شَهْبَاءُ فَرَكِبَهَا وَأَخَذَ عُقْبَةُ يَقُودُهَا بِهِ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم لِعُقْبَةَ " اقْرَأْ " . قَالَ وَمَا أَقْرَأُ يَا رَسُولَ اللَّهِ قَالَ " اقْرَأْ { قُلْ أَعُوذُ بِرَبِّ الْفَلَقِ * مِنْ شَرِّ مَا خَلَقَ } " . فَأَعَادَهَا عَلَىَّ حَتَّى قَرَأْتُهَا فَعَرَفَ أَنِّي لَمْ أَفْرَحْ بِهَا جِدًّا قَالَ " لَعَلَّكَ تَهَاوَنْتَ بِهَا " . فَمَا قُمْتُ يَعْنِي بِمِثْلِهَا .
sunnah.com