When does a traveler begin to avail himself of the dispensations of travel?

Question:
If a person intends to travel a long distance, when does the shortening of the prayer begin, and likewise breaking the fast in Ramadan? Does it begin when he leaves his house, or after he passes the distance for shortening, which is approximately eighty kilometers?

Answer:
If he intends to travel a distance of eighty kilometers or more, then the shortening of the prayer and breaking the fast in Ramadan begin when he leaves the town, specifically the inhabited part of the town. So, when he exits the boundaries of the inhabited town, it is permissible for him to shorten the prayer, and it is permissible for him to break his fast in Ramadan. However, as long as he is inside the town, it is not permissible for him to break his fast, nor is it permissible for him to shorten the prayer until he exits the town. This is because the word "travel" (safar) is derived from "uncovering" (sufur), which means emerging and appearing, and this is not realized unless he exits the town and emerges.