The passage discusses purification of vessels from non-Jewish ownership: vessels used on fire are purified by fire (to remove absorbed forbidden foods), while vessels used only for cold items are purified by passing through water, which the passage interprets as washing and scrubbing them thoroughly to remove residue of prohibited substances rather than as immersion.
תַּעֲבִירוּ בָאֵשׁ וְטָהֵר – אֵין הַכְּלִי שֶׁנָּגַע בַּמֵּת אוֹ בַּנְּבֵלָה נִטְהָר בָּאֵשׁ, שֶׁאֵין טְבִילַת הַתּוֹרָה אֶלָּא בַּמַּיִם. וּלְפִיכָךְ הֻצְרְכוּ רַבּוֹתֵינוּ (ע״ז עה) לְפָרֵשׁ שֶׁזּוֹ הַטָּהֳרָה לְהַגְעִילָם מֵאִסּוּרֵי הַמַּאֲכָלוֹת שֶׁבָּלְעוּ בְּיַד הַגּוֹיִים, וְזֶה אֱמֶת בְּלִי סָפֵק: וְכֹל אֲשֶׁר לֹא יָבֹא בָּאֵשׁ – כָּל דָּבָר שֶׁאֵין תַּשְׁמִישׁוֹ עַל יְדֵי הָאוּר, כְּגוֹן כּוֹסוֹת וּצְלוֹחִיּוֹת וְקִיתוֹנוֹת שֶׁתַּשְׁמִישָׁן בְּצוֹנֵן וְלֹא בָּלְעוּ אִסּוּר, תַּעֲבִירוּ בַמָּיִם – מַטְבִּילָן וְדַיּוֹ, לְשׁוֹן רַשִׁ״י (רש״י על במדבר ל״א:כ״ג). וְאֵינוֹ נָכוֹן בְּעֵינַי, שֶׁאֵין לְשׁוֹן "תַּעֲבִירוּ" טְבִילָה, כִּי הָיָה אוֹמֵר "תָּבִיאוּ בַמַּיִם", שֶׁהוּא לְשׁוֹן הַטְּבִילָה, כְּמוֹ ״בַּמַּיִם יוּבָא וְטָמֵא עַד הָעֶרֶב וְטָהֵר״ (ויקרא י״א, ל״ב). וְעוֹד, שֶׁאַף הַכֵּלִים שֶׁתַּשְׁמִישָׁן בְּצוֹנֵן צְרִיכִין הֶכְשֵׁר מִן הָאִסּוּר שֶׁבָּהֶן מִלְּבַד הַטְּבִילָה הַזּוֹ, וְאֵיךְ לֹא יַזְכִּיר הֶכְשֵׁרָן כַּאֲשֶׁר עָשָׂה בַּבָּאִים בָּאֵשׁ? וּכְשֶׁלָּמְדוּ חֲכָמִים טְבִילָה זוֹ לֹא הִזְכִּירוּ בָהּ הַמִּקְרָא הַזֶּה, אֶלָּא דָּרְשׁוּ (ע״ז שם): ״אַךְ בְּמֵי נִדָּה יִתְחַטָּא״ - מַיִם שֶׁהַנִּדָּה טוֹבֶלֶת בָּהֶם. אֲבָל פֵּרוּשׁ תַּעֲבִירוּ בַמָּיִם – לְכַבְּסָם וּלְשַׁפְשֵׁף אוֹתָם בַּמַּיִם יָפֶה עַד שֶׁתָּסוּר חֲלוּדָה שֶׁנִּדְבְּקָה מֵהֶם מִן הָאִסּוּר שֶׁנִּשְׁתַּמֵּשׁ בָּהֶם, שֶׁזֶּהוּ הֶכְשֵׁרָן מִן הָאִסּוּר. יֹאמַר הַכָּתוּב: דָּבָר שֶׁתַּשְׁמִישׁוֹ בָּאֵשׁ תָּבִיאוּ בָּאֵשׁ כְּדֶרֶךְ שֶׁהָיָה הַתַּשְׁמִישׁ בּוֹ בְּאִסּוּרוֹ - אִם תַּשְׁמִישׁוֹ בָּאוּר מַמָּשׁ, כְּגוֹן הַבַּרְזֶל וְהַנְּחֹשֶׁת וְגַם הַכֶּסֶף וְהַזָּהָב, מְלַבְּנוֹ בָּאוּר, וְאִם עַל יְדֵי חַמִּין כְּגוֹן הַבְּדִיל וְהָעוֹפֶרֶת, מַגְעִילוֹ בְּחַמִּין. וְדָבָר שֶׁלֹּא נִשְׁתַּמְּשׁוּ בוֹ בָּאֵשׁ אֶלָּא בְּצוֹנֵן, תָּדִיחוּ אוֹתוֹ בַּמַּיִם עַד שֶׁיִּתְמָרֵק וְיִטְהַר. וְכָךְ אָמְרוּ חֲכָמִים (שם) מְדִיחָן וּמַטְבִּילָן וְהֵן טְהוֹרִים, וּלְשׁוֹן סִפְרֵי (מטות נ): ״תַּעֲבִירוּ בָאֵשׁ״ - כְּגוֹן הַסַּכִּינִין מִפְּנֵי כְּוִיַּת הַגּוֹיִם, ״וְכֹל אֲשֶׁר לֹא יָבֹא בָאֵשׁ״ - כְּגוֹן הַכּוֹסוֹת "תַּעֲבִירוּ בַמָּיִם" מִפְּנֵי גִּעוּל הַגּוֹיִם. וְלֹא הֻצְרַךְ הַכָּתוּב לַחְזֹר וּלְהַזְכִּיר הַטְּבִילָה שֶׁכְּבָר הִזְכִּיר אוֹתָהּ ״אַךְ בְּמֵי נִדָּה יִתְחַטָּא״, וְאַחֲרֵי פְּלִיטַת הָאִסּוּר כֻּלָּם שָׁוִים בְּדִין הַטְּבִילָה. וְלִבִּי מְהַרְהֵר עוֹד לוֹמַר שֶׁהַטְּבִילָה הַזּוֹ מִדִּבְרֵיהֶם, וְהַמִּקְרָא אַסְמַכְתָּא עָשׂוּ אוֹתוֹ, וְכֵן אוּנְקְלוֹס (תרגום אונקלוס על במדבר ל״א:כ״ג) מְתַרְגֵּם אוֹתוֹ בְּחִטּוּי הַזָּאָה שֶׁל אֵפֶר פָּרָה. וְהִצְרִיכוּ אוֹתָהּ חֲכָמִים בִּכְלֵי הַמַּתָּכוֹת בִּלְבַד מִפְּנֵי שֶׁיֵּשׁ בָּהֶם כֵּלִים שֶׁתַּשְׁמִישָׁן בָּאוּר וּבִכְלִי רִאשׁוֹן וּבִכְלִי שֵׁנִי וּבְצוֹנֵן, וְזֶה צָרִיךְ תַּלְמוּד. וְהִזְהִיר אוֹתָם עַתָּה בְּהַגְעָלַת כְּלֵי מִדְיָן מֵאִסּוּרֵי הַגּוֹיִם, וְלֹא אָמַר לָהֶם זֶה מִתְּחִלָּה בִּכְלֵי סִיחוֹן וְעוֹג שֶׁלָּקְחוּ גַּם שְׁלָלָם, כְּמוֹ שֶׁאָמַר: ״רַק הַבְּהֵמָה בָּזַזְנוּ לָנוּ וּשְׁלַל הֶעָרִים אֲשֶׁר לָכָדְנוּ״ (דברים ב ל״ה). וְהַטַּעַם כִּי סִיחוֹן וְעוֹג מַלְכֵי הָאֱמוֹרִי הֵם וְאַרְצָם מִנַּחֲלַת יִשְׂרָאֵל הִיא, וְהֻתַּר לָהֶם כָּל שְׁלָלָם אֲפִלּוּ הָאִסּוּרִים, דִּכְתִיב: ״וּבָתִּים מְלֵאִים כָּל טוּב אֲשֶׁר לֹא מִלֵּאתָ״ (שם ו י״א), וְאָמְרוּ רַבּוֹתֵינוּ (חולין י״ז) קַדְלֵי דַּחֲזִירֵי אִשְׁתְּרֵי לְהוּ. אֲבָל מִדְיָן לֹא הָיָה מִשֶּׁלָּהֶם וְלֹא לָקְחוּ אֶת אַרְצָם, רַק לִנְקֹם נִקְמָתָם הָרְגוּ אוֹתָם וְלָקְחוּ שְׁלָלָם, וּלְכָךְ נָהַג הָאִסּוּר בִּכְלֵיהֶם. וְכֵן בְּדִין הַטֻּמְאָה שֶׁהִזְהִירָם עַתָּה: ״וְאַתֶּם חֲנוּ מִחוּץ לַמַּחֲנֶה שִׁבְעַת יָמִים״ וְגוֹ' (במדבר ל״א:י״ט), כִּי מִלְחֶמֶת סִיחוֹן וְעוֹג בָּהּ הָיוּ כָּל יִשְׂרָאֵל וְטֻמְאָה הֻתְּרָה בְּצִבּוּר. וְעַל דֶּרֶךְ הַפְּשָׁט הִזְהִירָם וְאַתֶּם חֲנוּ מִחוּץ לַמַּחֲנֶה שִׁבְעַת יָמִים וְתִתְחַטְּאוּ, כְּדֵי שֶׁלֹּא יְטַמְּאוּ אֶת הָעָם, אֲבָל שָׁם כֻּלָּם הָיוּ שָׁוִים בַּדָּבָר:
EVERY THING THAT MAY COME INTO THE FIRE YE SHALL PASS THROUGH THE FIRE AND IT SHALL BE CLEAN. A vessel which touched a human corpse or dead animal does not become purified by fire, since the immersion mentioned in the Torah is always in water. Therefore our Rabbis had to explain that this purification [mentioned here by Scripture] refers to remove from them [the traces of] the forbidden foods which they had absorbed whilst they were in the possession of the non-Jews. This is the true [explanation] without any doubt. AND ALL THAT COMETH NOT INTO THE FIRE — “anything which is not [normally] used on fire, such as cups, flasks, and pitchers which are used [to contain] cold substances, and [therefore] have not absorbed [any of the traces of forbidden foods] ye shall pass through the water, meaning that it is sufficient to immerse them.” This is Rashi’s language. But it does not appear to me to be correct, for the term ta’aviru (ye shall pass through) does not refer to immersion; for [had this been the case], it would have said “tavi’u (ye shall put it) into water,” which is the expression used in connection with immersion, just as it says, it ‘yuva’ (must be put into) water, and it shall be unclean until the even, and then it shall be clean. Furthermore, even those vessels, which are only used for cold things [of forbidden foods] need purification from [the traces of] their forbidden foods in addition to this immersion [which Rashi mentioned], and how can it be that Scripture [here] does not mention the [method] of purification [for such vessels] as it did with reference to those vessels that come into the fire? And when the Sages deduced [the necessity for] this immersion they did not mention that the source for it was this [part of the] verse [quoted here by Rashi], but interpreted it [on the basis of that part of the verse which says]: “Nevertheless it shall be purified with the waters of ‘niddah’ — waters which are fit for a niddah (a menstruant woman) to immerse herself in.” But the meaning of ye shall pass through the water is that you should wash them and rub them thoroughly in water until you remove the deposit of forbidden foods which has formed on the vessels by being used for such foods, and this [process] constitutes their purification from the forbidden foods. Scripture is thus saying that [in order to purify a vessel from the forbidden food which it has absorbed] you must put into fire those [vessels] which are used on the fire, in exactly the same way that they were used for [cooking] the forbidden foods. Hence if it was used on the flame itself — such as [a vessel of] iron or copper, and also silver or gold — he must make it white-hot in a flame, and if it was used to contain hot substances, such as [a vessel made of] tin or lead, he cleanses it with boiling-hot water; and if it was not used on fire [or for hot substances] but only for cold foodstuffs, he scours it with water until it is properly cleansed, and then it becomes pure. And similarly the Sages said: “He scours them, and immerses them, and they are then pure.” In the language of the Sifre: “Ye shall pass through the fire — such as knives, because they are [used as spits and] burned by the non-Jews. And all that cometh not into the fire, such as cups, ye shall pass through the water in order to remove the deposits of [the food of] the non-Jews.” And Scripture did not need to mention again [at this second part of the verse, i.e., and all that cometh ‘not’ into the fire], the necessity of immersion [in a ritual pool, which is required after cleansing the vessel before it can be used], because He had already mentioned [in the first part of the verse, concerning vessels that are used in the fire, stating]: nevertheless it shall be purified with the waters of ‘niddah’ [meaning, as explained above, “waters which are fit for ‘a menstruant’ woman to immerse herself in”], and [it is self-understood that] after the traces of forbidden foods have been removed from the vessels they are all alike with respect to the law [requiring] immersion [whether they were used in the fire or not]. And I further take into consideration that this immersion [of all vessels obtained from non-Jews, after they have been cleansed from the traces and absorption of forbidden foods prepared in them], is a law of the Rabbis, and they quoted the verse merely as a Scriptural support [for the Rabbinic ordinance]. And similarly Onkelos translated [the phrase, the waters of ‘niddah’] as meaning “the purification of ‘sprinkling’ of [the water containing] the ashes of the [Red] Heifer” [which was required in order to purify those who had come into contact with a dead body, and thus it does not refer at all to the requirement of immersion. The Rabbis [according to this explanation] only required immersion of metal vessels, because some of them are used on fire, either as a “first vessel” [used directly on the flame], or as a “second vessel” [i.e., those which are not actually used for cooking but into which a boiling substance has been put or poured], and [some metal vessels are used] for cold foodstuffs. But this matter needs further investigation. Now He warned them here to remove from the vessels of the Midianites the [traces and absorptions of the] forbidden foods [which they had absorbed when they were in the possession] of the non-Jews, but He did not tell them this [law] at the beginning — in connection with the vessels of [the Amorite peoples ruled by] Sihon and Og which they also took as spoil, as it is said, Only the cattle we took for a prey unto ourselves, with the spoil of the cities which we had taken. The reason for this is that Sihon and Og were Amorite kings, and their land was part of Israel’s inheritance, and therefore all spoil taken from them was allowed for the Israelites, including foods [usually] forbidden; for it is written, and houses full of all good things, which thou didst not fill, and our Rabbis have said: “kadlei of swine was [hereby especially] permitted for them.” But Midian was not part of their [inheritance], and they [the Israelites] did not capture their land from them; it was only to execute vengeance on them [as they were commanded to do as a punishment for causing the Israelites to sin] that they killed them and took their spoil, and therefore the [usual] prohibition of using their vessels [without removing from them the traces and absorptions of the forbidden foods] applied. Similarly, He [only] commanded them [now] about the law of impurity [conveyed by the dead, saying], And abide ye without the camp seven days etc. [and did not command them about it in the earlier war against Sihon and Og], because in the war against Sihon and Og all Israel participated, and when the [entire] public is involved, impurity is permitted, [whereas, as explained above in Verse 6, only a select few, and not the whole people, were sent to execute vengeance on Midian.] But according to the plain meaning of Scripture, He warned them [the twelve thousand men who fought against Midian], “And abide ye without the camp seven days and purify yourselves,” in order that they should not defile [the rest of] the people, but there [in the case of the wars against Sihon and Og] they were all equally impure [since they all went to fight; hence there was no point commanding them to abide without the camp, since they all required purification anyhow].