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.
Source: sunnah.com
Other translations
Arabic
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 .
sunnah.com