Tevul Yom, Chapter 4, Mishnah 6. Like the mishnah before it, this one is not about a tevul yom at all. It belongs here because of its form: a ruling the chachamim originally held, introduced by "barishona hayu omrim" (originally they used to say), followed by a later expansion, "chazru lomar" (they then said). The subject is a husband who instructs that a get be written for his wife, and how far we may read his intention.
Ordinarily, when a man says, "Write a get for my wife," we take his words at face value. He has appointed agents to write the document, and nothing more: he has not appointed anyone to deliver it to her. Writing and giving are two separate acts, and only what he actually said has been authorized.
"Barishona hayu omrim, hayotzei bakolar ve'amar kisvu get le'ishti, harei eilu yichtevu veyitnu." Originally the chachamim ruled that a man being led out in chains, taken off to imprisonment, is judged differently. When such a person says, "Write a get for my wife," his true intention is plainly not merely to have a document drawn up and left sitting there. He wants his wife to receive her get. So here we follow not only his words but his evident purpose: the get is written on his behalf and it is also delivered to his wife on his behalf.
"Chazru lomar, af hamefaresh vehayotzei beshayara." Later the chachamim extended this reading of a husband's intention beyond the man in chains. It applies as well to one who is setting out to sea on a voyage, and to one who is departing with a caravan on a long journey. Such a man, saying "Write a get for my wife," is likewise understood to mean write and deliver.
"Rabbi Shimon Shezuri omer, af hamesukan." Rabbi Shimon Shezuri adds one more case to the list: a dangerously ill person. When he instructs that a get be written for his wife, we presume that he too intends not only the writing but the giving, and the get is written and delivered on his behalf.
The thread running through the Mishnah is a sensitivity to circumstance. A man on the edge of departure, whether into captivity, onto a ship, out with a caravan, or into serious illness, is not fussing over legal formulas. He is trying to free his wife, and the halachah, in its later and broader formulation, hears what he means.