Demai, Chapter Five, Mishnah Two
In this mishnah a person wants to separate terumah and terumat maaser at the same time from his tevel, which is produce that we know has not been tithed. In other words, we are no longer discussing demai.
Terumah is supposed to be 1/50 of ones produce. Together with terumat maaser, which is 1/100 of ones produce, he must separate 3/100 or 1/33 of the produce.
One who wishes to separate terumah and the terumat maaser together:
1) He should take one thirty third and say:
2) One hundredth part of what is here, on this side is non-sacred produce (hullin), and the rest shall be terumah for the whole.
3) And the one hundred parts of non-sacred produce which is here on this side shall be tithe, and the rest that is next to it is tithe.
4) That which I made tithe shall become the terumat maaser for it.
5) The remainder will be hallah, and the second tithe tithe is to the north or to the south of it and that will be exchanged for money.
I shall explain this procedure step by step.
1) The first thing he does is take 1/33, or 3/100 of the produce and separate it from the rest.
2) Then he says that 1/100 (meaning 1/3 of that which he separated) remains, for the meanwhile, non-sacred produce and the rest, meaning the other 2/100, is terumah. In this way he has fulfilled the requirement to separate teruamh. Note that he has to designate the terumah before he designates the tithe or the terumat maaser, the terumah taken from the tithe.
3) He now says that the other 1/100 that he separated is tithe, as well as the other 9/100 parts that are next to it, but still attached to the loaf. In this way he has separated 1/10 of the loaf to be tithe. Note that he must designate tithe before he declares that that which he separated should be terumat maaser.
4) Then he says that the 1/100 part that he separated is terumat maaser for the tithe that he has just designated. He has now successfully separated terumah and terumat maaser, all of which goes to the priest.
5) The final section about separating hallah and second tithe is missing in most manuscripts of the mishnah. It was probably accidentally brought here from the previous mishnah. It has nothing to do with our subject.