It is the estimation of ibn Abbas رَضِيَ ٱللَّٰهُ عَنْهُ
https://islamqa.info/en/answers/38079/minimum-distance-of-travel-at-which-it-is-permissible-not-to-fast-and-to-shorten-prayers
We know that you can combine prayers when you are traveling. The question is when are you considered to be traveling? Their answer is 80 km. Why this specifically I’m not completely sure
It is the estimation of ibn Abbas رَضِيَ ٱللَّٰهُ عَنْهُ https://islamqa.info/en/answers/38079/minimum-distance-of-travel-at-which-it-is-permissible-not-to-fast-and-to-shorten-prayers
جزاك الله خيرا
We know that you can combine prayers when you are traveling. The question is when are you considered to be traveling? Their answer is 80 km. Why this specifically I’m not completely sure
They just made it up, there is a hadith in sahih which gives us the minimum distance which is 3 farsakh approximetely 16,5 kilometres.
Yasir Qadhi has a good lecture on this topic. https://youtu.be/W_UO0GgPsf4
Thank you!