Dear Eyal,

Two short introductions: 1. A person cannot leave his area of Techum (boundary) on Shabbos and holidays. One's personal items are bound to his Techum also. 2. Leaving one's the Techum results in losing the rights to move about (except for four Amos) even if the person intentionally returns to his original area.

The translation is: Items of Hefker (ownerless items) are like the feet of the new owner (if one takes such an item on Shabbos, they are given the new owner's Techum). A Nochri's items acquire the resting area in their place (wherever they were situated at the beginning of Shabbos or Yom Tov; this is a rabbinical decree that even though a Nochri's item has no Techum restrictions, it was given the rules of Techum in order that people not to be slack with Jewish-owned items).

Fruits (or other items, as opposed to people) that left the Techum and were brought back unlawfully, even if done intentionally, do not lose Techum rights, since such items are comparable to a person who was moved against his will (who does not lose his Techum rights).

Reuven Weiner