Halakhah for Bava Metzia 7:10
מֵתָה כְדַרְכָּהּ, הֲרֵי זֶה אֹנֶס. סִגְּפָהּ וָמֵתָה, אֵינוֹ אֹנֶס. עָלְתָה לְרָאשֵׁי צוּקִין וְנָפְלָה וָמֵתָה, הֲרֵי זֶה אֹנֶס. הֶעֱלָהּ לְרָאשֵׁי צוּקִין וְנָפְלָה וָמֵתָה, אֵינוֹ אֹנֶס. מַתְנֶה שׁוֹמֵר חִנָּם לִהְיוֹת פָּטוּר מִשְּׁבוּעָה, וְהַשּׁוֹאֵל לִהְיוֹת פָּטוּר מִלְּשַׁלֵּם, נוֹשֵׂא שָׂכָר וְהַשּׂוֹכֵר לִהְיוֹת פְּטוּרִין מִשְּׁבוּעָה וּמִלְּשַׁלֵּם:
If it died naturally, this is an oness. If he afflicted it [by not feeding it, or by leaving it out in the sun in the summertime, or in the cold in the wintertime], and it died, this is not an oness. If it [overpowered him and] went up to a high peak and fell off, this is an oness. If he took it up to a high peak and it fell off and died, this is not an oness. An unpaid watcher may make a condition to exempt himself from an oath; a borrower, to exempt himself from paying; a paid watcher and a hirer, to exempt themselves from an oath and from paying. [And this is not considered making a condition contrary to what is written in the Torah. For he tells him: "I consent to be your watcher only on this and this condition"; and one does not become a watcher until he pulls the beast (to effect acquisition). And this one, when he pulled the beast, had already stipulated that he (the owner) could not impose an oath upon him. He bound himself to be subject only to some of the laws of watchers; and he is liable only for these.]