International Standard Bible Encyclopedia (1915)
The common way of estimating distances in the East is by hours and days. This is natural in a country where roads are mere bridle paths or non-existent, as in the desert. The distance traveled must of course differ largely according to the difficulties of the way, and it is more important to know where night will overtake the traveler than the actual distance accomplished. A day’s journey is now commonly reckoned at about 3 miles per hour, the distance usually covered by a loaded mule, the number of hours being about 8. Hence, a day’s journey is about 24 miles, and this may be taken as a fair estimate for Bible times.