كتاب الإمارة
33
The Book on Government
(25)
Chapter: Horse Races and Training Horses for Racing
(25)
باب الْمُسَابَقَةِ بَيْنَ الْخَيْلِ وَتَضْمِيرِهَا ‏‏
Sahih Muslim 1870 a

It has been narrated on the authority of Ibn 'Umar that the Messenger of Allah (ﷺ) had a race of the horses which had been especially prepared for the purpose from Hafya' to Thaniyyat al-Wada' (the latter being the winning post), and of those which had not been trained from Thaniyya to the mosque of Banu Zuraiq, and Ibn Umar was among those who took part in this race.

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى التَّمِيمِيُّ، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، ‏.‏ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم سَابَقَ بِالْخَيْلِ الَّتِي قَدْ أُضْمِرَتْ مِنَ الْحَفْيَاءِ وَكَانَ أَمَدُهَا ثَنِيَّةَ الْوَدَاعِ وَسَابَقَ بَيْنَ الْخَيْلِ الَّتِي لَمْ تُضْمَرْ مِنَ الثَّنِيَّةِ إِلَى مَسْجِدِ بَنِي زُرَيْقٍ وَكَانَ ابْنُ عُمَرَ فِيمَنْ سَابَقَ بِهَا ‏.‏
Reference : Sahih Muslim 1870 a
In-book reference : Book 33, Hadith 139
USC-MSA web (English) reference : Book 20, Hadith 4610
  (deprecated numbering scheme)