Kelim, Chapter Twenty-Six, Mishnah Eight
1) The hides of a householder become susceptible to uncleanness by intention, but those that belong to a tanner do not become susceptible by mere intention.
2) Those taken by a thief become susceptible by intention, but those taken by a robber do not become susceptible by mere intention.
3) Rabbi Shimon says: the rule is to be reversed; those taken by a robber become susceptible by mere intention, but those taken by a thief do not become susceptible by intention, since in the latter case the owner does not abandon hope for recovery.
Section one: If a householder, a non-professional, owns a hide, as soon as he decides that it is ready for use it is susceptible to impurity (providing it is usable in its current state). However, the same is not true of a tanner. Even if he decides to use a hide before its processing is fully completed, it is still not susceptible to impurity for he is likely to change his mind and go back and finish the hide’s processing. In other words, since the tanner is a professional, he is less likely to be satisfied with less than perfect results. Therefore, his intention is less final.
Section two: A “thief” is a person who surreptitiously steals something. His identity will not be known to those from whom he stole. A “robber” is someone who violently takes something in broad daylight. His identity will be known.
According to the first opinion, if a thief steals something, the owners’ will lose all hope of getting it back because they don’t know who stole it. Therefore, the thief’s intentions determine whether the article is susceptible to impurity. But if a robber robs something, they will have hope of recovering the item, and therefore his intention is not determinative.
Section three: Rabbi Shimon reverses the reasoning expressed by the previous opinion. When a thief steals something, the owner hopes to get it back, because all he must do is discover who the thief is and he will be able to recover his item. But when a robber robs a person, right in front of their eyes and there was nothing they could do to stop it, the owner loses hope of recovering the item. [Notethere is little faith in any form of law enforcement]. Therefore, a robber’s intentions are determinative, and a thief’s are not.