Mishkat al-Masabih 19 Jihad كتاب الجهاد 79

وَعَن جَرِيرِ بْنِ عَبْدِ اللَّهِ قَالَ: رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَلْوِي نَاصِيَةَ فرسٍ بأصبعِه ويقولُ: ” الْخَيْلُ مَعْقُودٌ بِنَوَاصِيهَا الْخَيْرُ إِلَى يَوْمِ الْقِيَامَةِ: الأجْرُ والغَنيمةُ ” . رَوَاهُ مُسلم

Jarir b. ‘Abdallah told that he saw God’s Messenger twisting his finger in a horse’s forelock and saying, “The horses have good tied in their forelocks till the day of resurrection, i.e. reward and spoil.” Muslim transmitted it.