In Keilim 26:8, we read about how intention can in some cases bring about susceptibility to tumah.

עוֹרוֹת בַּעַל הַבַּיִת, מַחֲשָׁבָה מְטַמֵּאתָן. וְשֶׁל עַבְּדָן, אֵין מַחֲשָׁבָה מְטַמֵּאתָן.

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. [from Sefaria]

Bartenura explains that we suspect that the tanner will change their mind and thus the tanner's intention is not considered sufficient to induce susceptibility to tumah.

However, in Keilim 25:9, we see that intention cannot override intention.

כָּל הַכֵּלִים יוֹרְדִין לִידֵי טֻמְאָתָן בְּמַחֲשָׁבָה, וְאֵינָן עוֹלִים מִידֵי טֻמְאָתָן אֶלָּא בְשִׁנּוּי מַעֲשֶׂה, שֶׁהַמַּעֲשֶׂה מְבַטֵּל מִיַּד הַמַּעֲשֶׂה וּמִיַּד מַחֲשָׁבָה, וּמַחֲשָׁבָה אֵינָהּ מְבַטֶּלֶת לֹא מִיַּד מַעֲשֶׂה וְלֹא מִיַּד מַחֲשָׁבָה:

All vessels become susceptible to uncleanness by intention, but they cannot be rendered insusceptible except by a change-effecting act, for an act annuls an earlier act as well as an earlier intention, but an intention annuls neither an earlier act nor an earlier intention.

For example (as given in Kehati), if a person decided to use an animal's ring for a person, then it becomes susceptible to tumah, and if that person subsequently changes their mind, it doesn't lose its susceptibility.

Why don't we apply the principle that intention doesn't annul an earlier intention for a tanner, and say that their intention is sufficient to induce susceptibility to tumah? If the object in question will only ever be susceptible d'Rabbanan, I case see why the Rabbis might have made a distinction in this case (due to the perceived fickle nature of the tanner's intention); but when the object will become susceptible from Torah law, how can we be lenient here due to a doubt about the tanner's true intention?

  • If you're only half sure what you'll use it for, is that even called intention?
    – Double AA
    Jul 28, 2019 at 12:35

1 Answer 1


This Mishna is best explained using Rashi in Bava Kama 66b:

מחשבה מטמאתן - בעל הבית אינו עשוי למוכרן ועושה מהן מטות ודולבקאות וקטבלאות ומשחשב עליהן לדבר שראוי לו בלא חסרון מלאכה מקבלין טומאה מיד:‏

The householder can make his hides susceptible to uncleanness once he thinks about using them for something which requires no further work on the leather.

ושל עבדן - העשוי למכור אין מחשבתו מטמאתו דעביד דממליך ומזבין והלוקח יעשה מהם מנעלים ועדיין לא נגמרה מלאכתן לכך:‏

The Tanner does not make his hides susceptible to uncleanness by thinking about using them, since the buyer may use them for something else that requires further work on the leather.

The key here is the concept of גְמַר מְלָאכָה - an object does not become susceptible to uncleanness until it reaches גְמַר מְלָאכָה - a final state. As long as it still requires workmanship, it's not yet ready and not susceptible to uncleanness. This is the key to understanding a lot of Mishnayot related to utensils in the process of being manufactured.

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