Tevul Yom 4:6-7

T’vul Yom 4:6

If Ashkelon levers broke but their hooks remained, they remain susceptible to ritual impurity. If a pitchfork, a winnowing fan, a rake or a hair comb lost one of its teeth, which was replaced with one of metal, it is susceptible to impurity. Concerning all of these, Rabbi Yehoshua said that the Sofrim (Scribes) have introduced new laws for which he has no explanation. (This refers to all the laws from 4:2 until this point.)

T’vul Yom 4:7

Let’s say that someone was drawing trumah from a cistern and he said: “Let this be trumah on the condition that it comes up safely.” In such a case “safely” is understood to mean safe from being broken or spilled but not safe from ritual impurity; Rabbi Shimon says it also includes ritual impurity. If it breaks, it doesn’t create meduma (a mixture of trumah and chulin). How far from the cistern can it be broken without creating meduma? So far that if it rolls back, it would reach the cistern. Rabbi Yosi says that if one had the intention to make such a condition but he failed to do so and it broke, it doesn’t create meduma because this is a condition made by the court (on behalf of those who forget to do so).