I might think that removal (of the tithe) obtains on the seventh year, too; it is, therefore, written (26:12) "the year of the tithe" — the year when the tithe obtains, to exclude the seventh year, when the tithe does not obtain.
I might think that two tithes obtain in that year, (the first-tithe and the second-tithe); it is, therefore, written (Ibid. 26:12) "the year of the tithe": one tithe (of the two obtains), and not two.
This tells me only of the poor-tithe, of which the verse is speaking. Whence do I derive (for removal in the third year) the other tithes? From (Ibid.) "all the tithe of your produce."