To whom will they give this Terumah?
Radak: In the future, they will give it for Chanukas ha'Bayis.
Malbim: They will give to the Nasi, in addition to him receiving an Achuzah in the land. He will receive one part in 60, or one part in 100, or one part in 200.
What do we learn from "Shishis ha'Eifah me'Chomer ha'Chitim"?
Rashi: This is one part in 60. One may not give less than this for Terumah [Gedolah]; it is stingy to give one part in 60 1 (Terumos 4:3).
Radak: This will be the first Korban for the congregation for Chanukas ha'Mizbe'ach ? a Minchah. One who has a Chomer of wheat will separate for Hashem a sixth of an Eifah of flour, which is one part in 60 of a Chomer. Also for barley, he will separate a Minchah 2 of sixth of an Eifah of flour, which is one part in 60 of a Chomer.
Malbim: From wheat and barley, the Nasi will receive one part in 60.
Radak (15): This is mid'Rabanan; the Torah did not give a Shi'ur for Terumah Gedolah; one wheat kernel exempts the entire stack. Rashi's Perush is astounding. Why does Yechezkel teach the Shi'ur of one who is stingy? He should teach the intermediate Shi'ur, one part in 50! And why does it teach Terumah only for wheat and barley, and Ma'aser of oil ? it should have taught Degen, Tirosh v'Yitzhar, like the Torah says! Rather, so Hashem said that it will be in the future. The Navi taught about oil; the same applies to other liquids.
The Torah allows a Minchah of barley only for Minchas ha'Omer, and Minchas Sotah! Perhaps this will be a Hora'as Sha'ah for Chanukas ha'Mizbe'ach. (PF)
What do we learn from "v'Shishisem"?
Rashi: Divide one part in six of an Eifah to be Terumah for a Chomer of barley. Radak ? Shishisem is a verb (divide into six), just like "v'Chimesh Es Eretz Mitzrayim" (Bereishis 41:34) from Chamesh. Its grammatical form is like "v'Inisem" (Vayikra 16:31).