[After] he had made the first terumah withdrawal he covered [the remaining money] with leather covers; [after] the second [withdrawal] he covered [the remaining money] with leather covers; [but after] the third [withdrawal] he did not cover [the remaining money]. [The money is covered] lest he forget and withdraw from an accumulation from which [funds] had [al-ready] been withdrawn.  He withdrew the first terumah on behalf of [the inhabitants of] Eretz Yisrael, the second on behalf of [the inhabitants of] the cities surrounding it, and the third on behalf of [the inhabitants of] Babylon, Media, and the distant countries.

What did they do with the terumah? With it they would purchase daily offerings, additional offerings, and their nesachim; the Omer, the Two Loaves, and the Panim bread; and all the public offerings.  Those who watch over the aftergrowth of the Shemittah year receive their wages from the funds withdrawn from the [treasury] chamber.  R’ Yose says: Also, one wishing to, may volunteer as an unsalaried watchman.  They replied to him: You too admit that they must come from public assets.