How much does one need to distance his tree from another’s property? One reason for the distance is to leave room for the neighbor to plow. If one’s roots grow into a neighboring field, one can cut them to a certain distance depending on why one is cutting them (what one needs the space for). Various cases are brought discussing these halachot. The mishna says that when one is allowed to cut the roots of a neighbor’s tree, the wood from the roots goes to “him.” The gemara tries to figure out whether the “him” refers to the owner of the tree or the owner of the neighboring field. Ulla says that since roots of a tree will get nourishment from a neighboring field if it is within 16 cubits, one does not bring Bikurim from such a tree. The gemara tries to bring sources to see where he gets to that number from.