"The fullness of his handful" — one might think heaped up; the verse says "with his handful" (Leviticus 6:8). If "with his handful," one might think with the tips of his fingers; the verse says "the fullness of his handful," as people take a handful. How then? He folds his three fingers over the palm of his hand and takes the handful. For the pan offering and the deep-pan offering (in another reading, also for the broken pieces) he wipes off the excess with his thumb above and with his little finger below, and this is the hardest service in the Temple. As for what lies between the boundaries of the handful, what is its status? Of what is within, you need not ask, for it is certainly part of the handful; of what is outside, you need not ask, for it is certainly part of the remainder; the question is only of what lies between, and the matter is left in doubt. What does he do? He burns the handful by itself first, then burns what lies between the boundaries. For if you said the in-between portion first, perhaps it is part of the remainder, and then it would be remainder that became deficient; and the master said that remainder which became deficient between the taking of the handful and the burning — one does not burn the handful upon it. Even now we apply here, "whatever is partly given to the fires is under the prohibition do not burn it." He burns the in-between portion for the sake of wood, like Rabbi Eliezer who said of "for a pleasing aroma" (verse 12), you may not offer it up as an aroma, but you may offer it up for the sake of wood; and according to the Sages, what can be said? That they take the handful from the oily part. Rav Pappa said: it is obvious to me that "the fullness of his handful" means as people take a handful. Rav Pappa asked: if he took the handful with the tips of his fingers, what is the law? From the sides, what is the law? From below upward, what is the law? Let it stand undecided.
Measuring a Full Handful With Three Fingers
Yalkut Shimoni on Torah 449:3
מְלֹא קֻמְצוֹ, יָכוֹל מְבֹרָץ, תַּלְמוּד לוֹמַר (ויקרא ו, ח) "בְּקֻמְצוֹ", אִי "בְּקֻמְצוֹ" יָכוֹל בְּרָאשֵׁי אֶצְבְּעוֹתָיו, תַּלְמוּד לוֹמַר "מְלֹא קֻמְצוֹ", כִּדְקָמְצֵי אִינְשֵׁי, הָא כֵּיצַד חוֹפֶה שָׁלֹשׁ אֶצְבְּעוֹתָיו עַל פַּס יָדוֹ וְקוֹמֵץ. בְּמַחֲבַת וּבְמַרְחֶשֶׁת (בְּלִישְׁנָא אַחְרִינָא וּבִפְתִיתִין) מוֹחֵק בְּגֻדָּלוֹ מִלְמַעְלָה וּבְאֶצְבַּע קְטַנָּה מִלְּמַטָּה, וְזוֹ הִיא עֲבוֹדָה קָשָׁה שֶׁבַּמִּקְדָּשׁ, בֵּין הַבֵּינַיִם שֶׁל קֹמֶץ מַהוּ, דְּגַוָּאי לָא תִּיבָּעֵי לָךְ דְּוַדַּאי קֹמֶץ הוּא, דִּבְרָאֵי נַמִּי לָא תִּיבָּעֵי לָךְ דְּוַדַּאי שְׁיָרִים הוּא, כִּי תִּבָּעֵי דְּבֵינֵי וּבֵינֵי, הָדָר פָּשִׁיט בֵּין הַבֵּינַיִם סָפֵק. הֵיכִי עָבִיד, מַקְטִיר קֹמֶץ לְחוּדֵיהּ תְּחִלָּה, וְהָדָר מַקְטִיר בֵּין הַבֵּינַיִם, דְּאִי אָמַרְתְּ בֵּין הַבֵּינַיִם בְּרֵישָׁא דִּילְמָא שְׁיָרִים נִינְהוּ וְהָווּ לְהוּ שְׁיָרִים שֶׁחָסְרוּ, וְאָמַר מַר שְׁיָרִים שֶׁחָסְרוּ בֵּין קְמִיצָה לְהַקְטָרָה אֵין מַקְטִירִין עֲלֵיהֶן הַקֹּמֶץ. הַשְׁתָּא נַמִּי אִיקְרֵי כָּאן כָּל שֶׁמִמֶּנּוּ לָאִשִּׁים הֲרֵי הוּא בְּבַל תַּקְטִירוּ. דְּמַקְטִיר לְהוּ לְשֵׁם עֵצִים, כְּרַבִּי אֱלִיעֶזֶר דְּאָמַר (להלן פסוק יב) "לְרֵיחַ נִיחֹחַ", אִי אַתָּה מַעֲלֶה, אֲבָל אַתָּה מַעֲלֶה לְשֵׁם עֵצִים. לְרַבָּנָן מַאי אִיכָּא לְמֵימַר דְּקָמְצֵי שָׁמְנֵי. הַשְׁתָּא דְּאָתִית לְהָכִי לְרַבִּי אֱלִיעֶזֶר נַמִּי דְּקָמְצֵי שָׁמְנֵי. אָמַר רַב פַּפָּא, פְּשִׁיטָא לִי מְלֹא קֻמְצוֹ כִּדְקָמְצֵי אִינְשֵׁי. בָּעֵי רַב פַּפָּא קָמַץ בְּרָאשֵׁי אֶצְבְּעוֹתָיו מַהוּ, מִן הַצְּדָדִין מַהוּ, מִלְּמַטָּה לְמַעְלָה מַהוּ, תֵּיקוּ.