Mishnayos Shekalim Perek 4 Mishnah 1

At certain times of the year, half-shekels that had been donated to the Temple and stored in a chamber in the Temple were collected in order to be used for various purposes. The mishna asks: The collection of half-shekels, what would they do with it? They would purchase animals for the daily offerings, which were offered each morning and afternoon; and for the additional offerings, which were offered on Shabbat, the New Moon, and Festivals; and wine for their libations; barley for the omer meal-offering; and wheat for both the two loaves offered on Shavuot and the shewbread; and animals for all the communal offerings. § The guards of the sefiḥin, grain that grew without being purposely planted, during the Sabbatical Year, ensured that people did not take this ownerless grain, so that it remained available to be used for the omer and the offering of the two loaves. They collect their wages from the collection of the Temple treasury chamber. Rabbi Yosei says: One who so desires may even volunteer his services and guard the grain as an unpaid bailee. The Rabbis said to him: Even you must say that the omer and the two loaves come only from communal funds and not from any one individual. If one were to volunteer his services, he would acquire the grain for himself by guarding it and transporting it to the Temple. In that case, these offerings would have come from an individual. So that the offerings come solely from communal funds, the guards must receive payment from the half-shekels removed from the chamber.

הַתְּרוּמָה מֶה הָיוּ עוֹשִׂין בָּהּ, לוֹקְחִין בָּהּ תְּמִידִין וּמוּסָפִין וְנִסְכֵּיהֶם, הָעֹמֶר וּשְׁתֵּי הַלֶּחֶם וְלֶחֶם הַפָּנִים, וְכָל קָרְבְּנוֹת הַצִּבּוּר. שׁוֹמְרֵי סְפִיחִים בַּשְּׁבִיעִית, נוֹטְלִין שְׂכָרָן מִתְּרוּמַת הַלִּשְׁכָּה. רַבִּי יוֹסֵי אוֹמֵר, (אַף הָרוֹצֶה) מִתְנַדֵּב שׁוֹמֵר חִנָּם. אָמְרוּ לוֹ, אַף אַתָּה אוֹמֵר, שֶׁאֵינָן בָּאִין אֶלָּא מִשֶּׁל צִבּוּר: