Reference for Bava Kamma 63:5

אמר רבא ק"ו ומה יער שזה לרשותו נכנס וזה לרשותו נכנס נעשה כמי שנכנס לרשות חבירו וחייב זה שלרשות חבירו נכנס לא כל שכן

Raba [however] said: There is an <i>a fortiori</i> [to the contrary]: If in the case of the Wood,<span class="x" onmousemove="('comment',' Referring to Deut. XIX, 5: As when a man goeth into the wood with his neighbour to hew wood, and his hand fetcheth a stroke with the axe to cut down the tree and the head slippeth from the helve and lighteth upon his neighbour… cf. also infra p. 175 ');">⁴</span>

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