As we have seen, our perek has begun to deal with rabbinic enactments that were instituted to establish certain norms of behavior mipnei darkhei shalom – in order to keep the peace (see daf 59). Several of these enactments deal with cases of possession and ownership. If a child picks something up, can it be taken from him? If a poor person drops fruit to the ground from a tree, can someone take it or does it belong to him? In cases like these, even though it appears that there is no real kinyan, mipnei darkhei shalom we view these things as having been claimed. Rabbi Yossi believes that we view it as a full act of acquisition (at least on a rabbinic level) and that taking such an object is forbidden not only because of darkhei shalom, but because it would be actual theft.
One case from the Mishna that is discussed in our Gemara is the case of someone who sets traps for wild animals. When the animal is trapped, does it actually belong to the person who set the traps? Here too, we find a disagreement as to whether taking it is forbidden because of darkhei shalom or because it is actual theft. Our Gemara points out that there are different types of traps. Nets and traps that actually hold the animal within them are certainly viewed as having brought the animal into the possession of the trapper, and taking an animal from such a trap would be stealing. The argument is in the case of lehi ve-kokri.
Rashi explains that a lehi is a hook while kokri is a long string that holds many hooks. The Ge’onim suggest that kokri is a stone board that is leaned on a stick that has bait attached to it. When the bait is pulled away, the heavy board falls on the animal and traps it.
According to the Talmud Yerushalmi all agree that in the case of a trap that is small in size, where the animal is readily taken out by the trapper, the trapper has taken possession of the animal and it belongs to him. In a case where the trap is large and the trapper will need to chase the animal even once it has entered the trap, we do not perceive him as having taken full possession of the animal and we will have the disagreement between the Tanna Kamma and Rabbi Yossi.