(Mishnah): One cannot separate Terumah from (the three gifts to the poor of) Leket, Shichechah, Peah or Hekfer (ownerless produce), nor from Maaser Rishon that has had its Terumas Maaser removed, nor from Maaser Sheni or Hekdesh that were redeemed, nor from that which is obligated for that which is exempt or vice-versa, nor from detached for attached produce or vice-versa, nor from new produce for old produce or vice-versa, nor from produce of Eretz Yisrael for produce of Chutz LaAretz or vice-versa. If a person did separate such Terumah, it is invalid.

(Gemara) (R. Yochanan citing R. Yannai): This is one of three pesukim concerning Terumah expounded in the Torah - (Devarim 14:29), "And the Levi will come, as he does not have portion and inheritance with you'' - this teaches that the only thing that is obligated in Ma'asros is if you have a portion but the Levi does not have a portion in it. This excludes ownerless land, for which your hand and his hand are equal. Leket, Shichechah and Peah are excluded for the same reason.

Question: Why did the Mishnah teach the case of 'from that which is obligated for that which is exempt'? All of the other cases in the Mishnah are examples of that?!

Answer: That case is referring to not separating Terumah from produce that has grown to 1/3rd of its growth for produce that has not.

The Mishnah taught that in all of the cases, if one separated Terumah in that way, it is invalid.

The Gemara earlier (see Chulin 56(j)&(k) - brought a disagreement between Chizkiyah and R. Yochanan about Beis Shammai's view concerning olives, grapes and other species) According to Chizkiyah, this is according to all opinions. According to R. Yochanan, it fits into the same disagreement as earlier.

(Mishnah): Five should not separate Terumah, but if they did, it is valid - a mute, a drunk person, someone unclothed, a blind person and a Baal Keri (someone who had a seminal emission).

One does not separate Terumah according to measure, weight or number (as it must be done through estimation), but one can measure, weigh or count his Tevel and separate its Terumah by estimation.

One may not separate using a basket or box, since they can be used to measure, but one may separate a half or third basket/box.

One may not separate using a Seah measure, even to measure half (as there is often a marking to indicate the half way point of the measure).

(Gemara): Some of the list are because of the Bracha and some are because they cannot separate from the best produce. A mute, someone unclothed and a Baal Keri cannot recite the Brocha. A drunk person and a blind person cannot separate from the best produce.

(Abba bar Rav Huna): One who drank wine should not pray, but if he did, his prayers are supplications. But if a person became drunk, he shouldn't pray, and if he did, his prayers were considered blaspheming. How much is considered that he drank wine? A Reviis of wine (86cc). What is considered drunk? If he drank more than that. In Bavel they defined it as whoever cannot speak before a king.

Question (R. Zeira to R. Isi): May a drunk person recite Birchas HaMazon?

Answer (R. Isi): The pasuk states (Devarim 8:10), "And you shall eat, you shall be satisfied and you shall bless'' - one who is satiated could sometimes be drunk and the Torah still obligated him.

The doubt wasn't about Birchas HaMazon; it was about whether one may recite the Shema when drunk.

(Abba bar Avin): A pious person once asked Eliyahu HaNavi - may an unclothed person recite the Shema?

Answer (Eliyahu): The pasuk states (Devarim 23:15), "There shouldn't been seen an Ervas Davar (shameful thing) amongst you'' -it is expounded as Ervas Dibur (a shameful word - i.e. words of Torah when you are unclothed).

Baraisa (Chizkiyah): It is prohibited both to recite Shema and to say its blessings.