Sheikh Muhammad Muhammad Sâlim `Abd al-Wadûd
Many scholars are of the opinion that a traveler cannot shorten his prayers or break his fast unless he is undertaking a journey of at least 88 kilometers.
The chief line of evidence cited by scholars who hold this view is as follows:
1. It is narrated with a weak line of transmission that the Prophet (peace be upon him) said: “People of Mecca! Do not shorten your prayers on a journey of less that four barîd – the distance between Mecca and `Asfân.” [Mu`jam al-Tabarânî al-Kabîr (11162), Sunan al-Dâraqutnî (1/387), and Sunan al-Bayhaqî (3/137)]
2. Though the hadîth is weak, this ruling is established as being the opinion of the Companion Ibn `Abbâs.
When people asked him if they could shorten their prayers on the way from Mecca to `Arafah, he replied: “No. But you can do so if you are going to `Asfân, Jeddah, or Ta’if.” [al-Talkhîs al-Habîr (2/46)]
3. It was the practice of both Ibn `Abbâs and Ibn `Umar to shorten their prayers and break their fasts whenever they undertook a journey of more than four barîd.
Ibn `Umar, for instance, shortened his prayers on a journey from Madinah to the town of Dhât al-Nasb, which was at a distance of four barîd. [Fath al-Bârî (2/566)]
One barîd is equal to 22.176 km. This means that four barîd equals 88.704 km. This is where that number comes from.
This distance is, in fact, roughly the distance between Mecca and Jeddah.
It is important to understand that those who set this as a minimum distance for a journey are talking about the full distance of the journey one-way, and not the distance when a person can start shortening his prayers. He can start shortening his prayers as soon as he departs from his own locality, as long as the journey he is taking is at least 88 km long.
It is also important to note that this distance of 88 km is not something that all scholars agree upon. There is considerable disagreement on this matter from the earliest times to the present. There are roughly twenty different scholarly views on the issue.
And Allah knows best.
Source: Islam Today