question #2 Sahih al-Bukhari 2870, Book 56, Hadith 86 : How were horse races organized and what were the typical distances covered in these races?

“Allah’s Messenger (ﷺ) arranged a horse race amongst the horses that had been made lean, letting them start
from Al-Hafya’ and their limit (distance of running) was up to Thaniyat-al-Wada`. I asked Musa,
‘What was the distance between the two places?’ Musa replied, ‘Six or seven miles. He arranged a race
of the horses which had not been made lean sending them from Thaniyat-al-Wada`, and their limit
was up to the mosque of Bani Zuraiq.’ I asked, ‘What was the distance between those two places?’ He
replied ‘One mile or so.’ Ibn `Umar was amongst those who participated in that horse race.”