Sahih al-Bukhari 6089, 6090
Narrated Jarir:
The Prophet (ﷺ) did not screen himself from me (had never prevented me from entering upon him) since I 
embraced Islam, and whenever he saw me, he would receive me with a smile. Once I told him that I 
could not sit firm on horses. He stroked me on the chest with his hand, and said, "O Allah! Make him 
firm and make him a guiding and a rightly guided man.
حَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا ابْنُ إِدْرِيسَ، عَنْ إِسْمَاعِيلَ، عَنْ قَيْسٍ، عَنْ جَرِيرٍ، قَالَ مَا حَجَبَنِي النَّبِيُّ صلى الله عليه وسلم مُنْذُ أَسْلَمْتُ، وَلاَ رَآنِي إِلاَّ تَبَسَّمَ فِي وَجْهِي‏.‏
وَلَقَدْ شَكَوْتُ إِلَيْهِ أَنِّي لاَ أَثْبُتُ عَلَى الْخَيْلِ، فَضَرَبَ بِيَدِهِ فِي صَدْرِي وَقَالَ ‏
"‏ اللَّهُمَّ ثَبِّتْهُ وَاجْعَلْهُ هَادِيًا مَهْدِيًّا ‏"‏‏.‏