Bava Metzia 41A

צריך דעת בעלים.

One requires the knowledge of the owner for the item to be considered returned.

אי רבי ישמעאל, מאי איריא לא יחדו? אפילו יחדו נמי!

The Talmud asks: If the baraita is in accordance with the opinion of R' Yishmael, why did the tanna in the first clause of the Mishnah establish the case specifically where the owner did not designate a specific place for the jug to be stored in the bailee’s house? Even in a case where the owner designated a place for the jug, the bailee should be exempt because he replaced the jug.

לא מיבעיא קאמר: לא מיבעיא יחדו דמקומה הוא, אלא אפילו לא יחדו דלאו מקומה הוא ⁠– לא בעינן דעת בעלים.

The Talmud answers: The tanna is speaking utilizing the style: It is not necessary. It is not necessary to state the halakha in a case where the owners designated a place for the jug, as after the bailee replaced the jug, that is its place. But even in a case where the owner did not designate a place for the jug, and after the bailee replaces the jug that is not its place, we do not require the knowledge of the owners. In both cases, once he replaces the jug, he is exempt from payment.

אימא סיפא: יחדו לה הבעלים מקום וטלטלה ונשברה, בין מתוך ידו, בין משהניחה, לצרכו ⁠– חייב, לצרכה ⁠– פטור. אתאן לרבי עקיבא, דאמר: בעינן דעת בעלים.

The Talmud asks: Say the latter clause of the Mishnah: If the owners designated a specific place for the jug, and the bailee moved it and it broke, whether it broke while still in his hand or whether it broke after he replaced the jug, if he moved it for his purposes he is liable to pay, and if he moved it for its own purposes, he is exempt. We arrive at the opinion of R' Akiva, who says: We require the knowledge of the owners. Since the bailee moved the jug from its place for his own purposes, he is a robber and is responsible for damages.