Ta'am Ke'Ikar and Hechsher Keilim

(א) וַיְדַבֵּ֥ר ה' אֶל־מֹשֶׁ֥ה לֵּאמֹֽר׃ (ב) נְקֹ֗ם נִקְמַת֙ בְּנֵ֣י יִשְׂרָאֵ֔ל מֵאֵ֖ת הַמִּדְיָנִ֑ים אַחַ֖ר תֵּאָסֵ֥ף אֶל־עַמֶּֽיךָ׃..(ז) וַֽיִּצְבְּאוּ֙ עַל־מִדְיָ֔ן כַּאֲשֶׁ֛ר צִוָּ֥ה ה' אֶת־מֹשֶׁ֑ה וַיַּֽהַרְג֖וּ כָּל־זָכָֽר׃ ...(י) וְאֵ֤ת כָּל־עָרֵיהֶם֙ בְּמ֣וֹשְׁבֹתָ֔ם וְאֵ֖ת כָּל־טִֽירֹתָ֑ם שָׂרְפ֖וּ בָּאֵֽשׁ׃ (יא) וַיִּקְחוּ֙ אֶת־כָּל־הַשָּׁלָ֔ל וְאֵ֖ת כָּל־הַמַּלְק֑וֹחַ בָּאָדָ֖ם וּבַבְּהֵמָֽה׃ (יב) וַיָּבִ֡אוּ אֶל־מֹשֶׁה֩ וְאֶל־אֶלְעָזָ֨ר הַכֹּהֵ֜ן וְאֶל־עֲדַ֣ת בְּנֵֽי־יִשְׂרָאֵ֗ל אֶת־הַשְּׁבִ֧י וְאֶת־הַמַּלְק֛וֹחַ וְאֶת־הַשָּׁלָ֖ל אֶל־הַֽמַּחֲנֶ֑ה אֶל־עַֽרְבֹ֣ת מוֹאָ֔ב אֲשֶׁ֖ר עַל־יַרְדֵּ֥ן יְרֵחֽוֹ׃(כא) וַיֹּ֨אמֶר אֶלְעָזָ֤ר הַכֹּהֵן֙ אֶל־אַנְשֵׁ֣י הַצָּבָ֔א הַבָּאִ֖ים לַמִּלְחָמָ֑ה זֹ֚את חֻקַּ֣ת הַתּוֹרָ֔ה אֲשֶׁר־צִוָּ֥ה ה' אֶת־מֹשֶֽׁה׃ (כב) אַ֥ךְ אֶת־הַזָּהָ֖ב וְאֶת־הַכָּ֑סֶף אֶֽת־הַנְּחֹ֙שֶׁת֙ אֶת־הַבַּרְזֶ֔ל אֶֽת־הַבְּדִ֖יל וְאֶת־הָעֹפָֽרֶת׃ (כג) כָּל־דָּבָ֞ר אֲשֶׁר־יָבֹ֣א בָאֵ֗שׁ תַּעֲבִ֤ירוּ בָאֵשׁ֙ וְטָהֵ֔ר אַ֕ךְ בְּמֵ֥י נִדָּ֖ה יִתְחַטָּ֑א וְכֹ֨ל אֲשֶׁ֧ר לֹֽא־יָבֹ֛א בָּאֵ֖שׁ תַּעֲבִ֥ירוּ בַמָּֽיִם׃

(1) The LORD spoke to Moses, saying, (2) “Avenge the Israelite people on the Midianites; then you shall be gathered to your kin.”... (7) They took the field against Midian, as the LORD had commanded Moses, and slew every male... (10) And they destroyed by fire all the towns in which they were settled, and their encampments. (11) They gathered all the spoil and all the booty, man and beast, (12) and they brought the captives, the booty, and the spoil to Moses, Eleazar the priest, and the whole Israelite community, at the camp in the steppes of Moab, at the Jordan near Jericho... (21) Eleazar the priest said to the troops who had taken part in the fighting, “This is the ritual law that the LORD has enjoined upon Moses: (22) Gold and silver, copper, iron, tin, and lead— (23) any article that can withstand fire—these you shall pass through fire and they shall be clean, except that they must be cleansed with water of a Mikvah; and anything that cannot withstand fire you must pass through water.

יליף מגיעולי עובדי כוכבים דאמר רחמנא (במדבר לא, כג) כל דבר אשר יבא באש למימרא דאסירי גיעולי עובדי כוכבים לאו טעמא בעלמא הוא ואסור הכא נמי לא שנא
Rabbi Akiva derives the principle: The legal status of the flavor of forbidden food is like that of the substance itself, from the vessels of gentiles that require purging [gi’ulei], where the Jews were commanded to purge the non-kosher flavor from the vessels they seized from the Midianites. As the Merciful One states in the section of the Torah that deals with the spoils of Midian: “Every thing that passes through the fire, you shall make it pass through the fire” (Numbers 31:23). That is to say that the vessels of gentiles that require purging are forbidden to be used until they have been purged through fire and purified. Isn’t there mere taste absorbed in the vessels through the process of cooking? And even so, these vessels are forbidden if this purging was not performed. Here, too, with regard to other matters of Torah law, it is no different; and the legal status of the flavor is like that of the substance itself.