Mishnah 1א׳
קָדְשֵׁי הַמִּזְבֵּחַ מִצְטָרְפִין זֶה עִם זֶה לִמְעִילָה, וּלְחַיֵּב עֲלֵיהֶן מִשּׁוּם פִּגּוּל, נוֹתָר וְטָמֵא. קָדְשֵׁי בֶדֶק הַבַּיִת מִצְטָרְפִין זֶה עִם זֶה. קָדְשֵׁי הַמִּזְבֵּחַ וְקָדְשֵׁי בֶדֶק הַבַּיִת מִצְטָרְפִין זֶה עִם זֶה לִמְעִילָה:
[Different] sanctified items intended to be offered on the altar combine with each other for the purposes of meilah and to make one liable for piggul [a sacrifice that becomes unfit, due to the intention of the officiating priest, while offering it, to consume it after its permitted time], notar [a sacrifice that becomes unfit, due to being left unconsumed until after the time limit for its consumption]and tamei [a sacrifice that becomes unfit because it has become defiled]. [Different] sanctified items for the maintenance of the Temple combine with each other. Items sanctified to be offered on the altar and items sanctified for the maintenance of the Temple treasury can combine with each other to make one liable for meilah.
Mishnah 2ב׳
חֲמִשָּׁה דְבָרִים בָּעוֹלָה מִצְטָרְפִין זֶה עִם זֶה. הַבָּשָׂר, וְהַחֵלֶב, וְהַסֹּלֶת, וְהַיַּיִן, וְהַשָּׁמֶן. וְשִׁשָּׁה בַּתּוֹדָה. הַבָּשָׂר, וְהַחֵלֶב, וְהַסֹּלֶת, וְהַיַּיִן, וְהַשֶּׁמֶן, וְהַלָּחֶם. הַתְּרוּמָה, וּתְרוּמַת מַעֲשֵׂר, וּתְרוּמַת מַעֲשֵׂר שֶׁל דְּמַאי, הַחַלָּה, וְהַבִּכּוּרִים, מִצְטָרְפִין זֶה עִם זֶה לֶאֱסֹר וּלְחַיֵּב עֲלֵיהֶן אֶת הַחֹמֶשׁ:
Five parts of an olah combine with each other for [liability], the meat, the chelev [fats around the stomach, intestines, and kidneys of some animals which are forbidden for eating], the flour, the wine and the oil, while six parts [combine with each other] by a todah [a special form of Shelamim offering accompanied by many loaves of various forms of bread, both leavened and unleavened, brought in thanks for emerging alive and well from one of several specified dangers considered particularly threatening], the meat, the chelev, the flour, the wine , the oil, and the [loaves] of bread.
Mishnah 3ג׳
כָּל הַפִּגּוּלִין מִצְטָרְפִין זֶה עִם זֶה. כָּל הַנּוֹתָרִין מִצְטָרְפִין זֶה עִם זֶה. כָּל הַנְּבֵלוֹת מִצְטָרְפוֹת זוֹ עִם זוֹ. כָּל הַשְּׁרָצִים מִצְטָרְפִין זֶה עִם זֶה. דַּם הַשֶּׁרֶץ וּבְשָׂרוֹ מִצְטָרְפִין. כְּלָל אָמַר רַבִּי יְהוֹשֻׁעַ, כֹּל שֶׁטֻּמְאָתוֹ וְשִׁעוּרוֹ שָׁוִין, מִצְטָרְפִין זֶה עִם זֶה. טֻמְאָתוֹ וְלֹא שִׁעוּרוֹ, שִׁעוּרוֹ וְלֹא טֻמְאָתוֹ, לֹא טֻמְאָתוֹ וְלֹא שִׁעוּרוֹ, אֵין מִצְטָרְפִין זֶה עִם זֶה:
All foods that are pigul combine with each other. All [foods] that are notar combine with each other. All neveilot [improperly slaughtered animals of a permitted species],combine with each other. All sheratzim[creeping animals] combine with each other. The blood of a sheretz and its flesh combine with each other. Rabbi Yehoshua said a general rule: anything whose transmission of impurity and its [minimum] measure [to make something else impure] are the same, they can combine [with each other]. If their transmission of impurity is the same, but their [minimum] measure [to make something else impure] is not the same, [or if their minimum] measure [to make something else impure] is the same but their transmission of impurity is not the same, they do not combine.
Mishnah 4ד׳
הַפִּגּוּל וְהַנּוֹתָר אֵין מִצְטָרְפִין זֶה עִם זֶה, מִפְּנֵי שֶׁהֵם שְׁנֵי שֵׁמוֹת. הַשֶּׁרֶץ וְהַנְּבֵלָה, וְכֵן הַנְּבֵלָה וּבְשַׂר הַמֵּת, אֵין מִצְטָרְפִין זֶה עִם זֶה לְטַמֵּא אֲפִלּוּ כַקַּל שֶׁבִּשְׁנֵיהֶם. הָאֹכֶל שֶׁנִּטְמָא בְאַב הַטֻּמְאָה וְשֶׁנִּטְמָא בִוְלַד הַטֻּמְאָה, מִצְטָרְפִין זֶה עִם זֶה לְטַמֵּא כַקַּל שֶׁבִּשְׁנֵיהֶם:
Piggul and notar do not combine because they have two different names. Creeping animal and animals which died without being properly slaughtered and similarly animals which died without being properly slaughtered and the meat of a dead animal do not combine to transmit impurity, even in the more lenient [feature] of the two. Food that have become impure through [by coming in contact with] an av hatumah [Primary source of impurity which renders even vessels and persons impure, all the more so foodstuffs] or that have become impure through [by coming in contact with] a velad hatumah [something rendered impure on a derivative level, by contact ultimately with an original source of impurity] can combine with each other to transmit impurity as the more lenient of the two.