690. Eating or Expelling Across Domains

Shabbos 13:2

One’s hand is the functional equivalent of a place four handbreadths by four handbreadths (about one foot on each side). Therefore, if a person removes something from another person's hand in one type of domain (public or private) and places it in the hand of a third party in the other type of domain, he is liable. Similarly, if someone was standing in one type of domain and he stretched his hand into the other type of domain and took an object from there, or from the hand of someone standing in that other domain, and he then pulled his hand back, he is liable. This is so even if he did not put the object down in the domain where he is standing; since the item is in his hand, it is considered the same as if he placed it on the ground.

Shabbos 13:3

If a person was eating and he traveled from one type of domain (public or private) to the other, he is liable if he decided to carry the food between domains in his mouth. While this is not a normal way to transport objects, his intention makes his mouth the equivalent of a place four handbreadths by four handbreadths. Similarly, if someone was standing in one type of domain and he urinated or spit into the other type of domain, he is liable because he moved something from one domain and put it down in the other. Because of his intention, it is considered as if he transported something from a four-handbreadth by four-handbreadth space. If a man stood in one type of domain and the opening of his urethra was in the other type of domain and he urinated into that second domain, he is not liable.