Sifrei Bamidbar 5

(Bamidbar 5:9) "And all terumah of all the holy things of the children of Israel which they present to the Cohein, to him shall it be." R. Yishmael says: Scripture comes to teach you that if one dedicates (to the Temple) his grain pile before he levels it off and then he redeems it, he must take terumah (from it). I might think (he must do so) even if he redeemed it after he leveled the pile; it is, therefore, written (of terumah, Devarim 18:4) "the first of your corn (pile)." R. Akiva says: "and all terumah": Scripture comes to teach you that if he wishes to make his entire granary terumah, he may do so, so long as he leaves some over. "and all terumah of all the holy things": Scripture hereby teaches us that the laws of terumah apply to all varieties (of produce, and not just to those specifically indicated). Issi b. Yehudah says: If the ma'aser — the less stringent — obtains with all produce, how much more so, terumah — the more stringent. Variantly: If ma'aser, which does not obtain in the third and sixth year (of shemitah), obtains with all produce, how much more so, terumah, which obtains in all years! Issi b. Menachem says: if ma'aser, which is brought only as an adjunct to learning and fear (viz. Devarim 14:23), obtains with all produce, how much more so, the more stringent, terumah! (Ibid. 5:9) "which they offer to the Cohein, to him shall it be": R. Yishmael says: Now is terumah offered to the Cohein? (Does he not rather come to receive it?) What, then, is the intent of "which they offer to the Cohein"? Because it is written (Shemot 23:19) "The first of the first-fruits (bikkurim) of your land shall you bring to the house of the L-rd your G-d," but we are not told what is to be done with them; it is, therefore, written "which they offer to the Cohein, to him shall it be." Scripture hereby teaches us that bikkurim, (which are presented as offerings), are to be given to the Cohanim.