[If] one rents a cow to plow on the mountains, and he plows in the valley —- if the colter breaks, he is exempt. [If he rents it to plow] in the valley, and he plows on the mountains —- if the colter breaks, he is liable; to thresh beans, and he threshes grain, he is exempt; to thresh grain, and he threshes beans, he is liable, because beans are slippery.

[If] one rents a donkey on which to bring wheat, and he brings barley on it, he is liable; grain, and he brings straw on it, he is liable, because the added bulk is difficult to carry. [If he rents it] to bring a lesech of wheat, and he brings a lesech of barley, he is exempt; but if he added to its load, he is liable. How much must he add to its load to be liable? Sumchos says in the name of R’ Meir: A seah for a camel, three kavs for a donkey.