Reference for Tahorot 10:4
הַנּוֹתֵן מִן הַסַּלִּים וּמִן הַמַּשְׁטֵחַ שֶׁל אֲדָמָה, בֵּית שַׁמַּאי אוֹמְרִים, נוֹתֵן בְּיָדַיִם טְהוֹרוֹת. וְאִם נָתַן בְּיָדַיִם טְמֵאוֹת, טִמְּאָן. בֵּית הִלֵּל אוֹמְרִים, נוֹתֵן בְּיָדַיִם טְמֵאוֹת, וּמַפְרִישׁ תְּרוּמָתוֹ בְּטָהֳרָה. מִן הָעֲבַט וּמִן הַמַּשְׁטֵחַ שֶׁל עָלִים, הַכֹּל שָׁוִים שֶׁהוּא נוֹתֵן בְּיָדַיִם טְהוֹרוֹת. וְאִם נָתַן בְּיָדַיִם טְמֵאוֹת, טִמְּאָן:
If one takes [grapes to the vat for pressing] from a basket or from an area on the ground designated for spreading them out, Beit Shammai says: he must take them with pure hands, and if he took them with impure hands he has rendered them impure. Beit Hillel says: he may take them with impure hands, and he separates his <i>terumah</i> from them in purity. If [one takes the grapes to the vat] from the large basket [into which the grapes are harvested, before being brought to the wine press] or from a leaf-covered area designated for spreading them out, everyone is in agreement that he must take them with pure hands, and if he took them with impure hands he has rendered them impure.