Shabbat 2A

מתני׳ יציאות השבת, שתים שהן ארבע בפנים, ושתים שהן ארבע בחוץ.

Mishnah: The acts of carrying out from a public domain into a private domain or vice versa, which are prohibited on Shabbat, are primarily two basic actions that comprise 4 cases from the perspective of a person inside a private domain, and two basic actions that comprise 4 cases from the perspective of a person outside, in a public domain.

כיצד?

The Mishnah elaborates: How do these 8 cases take place? In order to answer that question, the Mishnah cites cases involving a poor person and a homeowner.

העני עומד בחוץ, ובעל הבית בפנים: פשט העני את ידו לפנים ונתן לתוך ידו של בעל הבית, או שנטל מתוכה והוציא ⁠— העני חייב ובעל הבית פטור.

The poor person stands outside, in the public domain, and the homeowner stands inside, in the private domain. The poor person lifted an object in the public domain, extended his hand into the private domain, and placed the object into the hand of the homeowner. In that case, the poor person performed the prohibited labor of carrying from the public domain into the private domain in its entirety. Or, the poor person reached his hand into the private domain, took an item from the hand of the homeowner, and carried it out into the public domain. In that case, the poor person performed the prohibited labor of carrying out from the private domain into the public domain in its entirety. In both of these cases, because the poor person performed the prohibited labor in its entirety, he is liable and the homeowner is exempt.

פשט בעל הבית את ידו לחוץ ונתן לתוך ידו של עני, או שנטל מתוכה והכניס ⁠— בעל הבית חייב והעני פטור.

The Mishnah cites two additional cases. In these, the prohibited labor is performed by the homeowner, who is in the private domain: The homeowner lifted an item in the private domain, extended his hand into the public domain, and placed the object into the hand of the poor person. In that case, the homeowner performed the labor of carrying out from the private domain into the public domain in its entirety. Or, the homeowner reached his hand into the public domain, took an object from the hand of the poor person, and carried it into the private domain. In that case, the homeowner performed the labor of carrying from the public domain into the private domain in its entirety. In both of those cases, because the homeowner performed the prohibited labor in its entirety, he is liable and the poor person is exempt.