When is "ba'Yom ha'Hu"?
Rashi: It is after will cease the beautiful ornaments of adulteresses and base women. Then, [the nation's] beauty will not be valued via these.
Radak: It is the day of salvation when the redeemer will come/
What is "Tzemach Hashem", and what does the verse say about it?
Rashi: They are the Tzadikim and Chachamim who will remain. The nation will attribute the beauty of their honor to them.
Radak: It is Mashi'ach ben David - "va'Hakimosi l'David Tzemach Tzadik" (Yirmeyah 23:5).
Radak citing Targum Yonasan: It is the Mashi'ach of Hashem.
Malbim: The generation that will remain. The Tzadikim who will be found in it will be the beauty and honor of Beis Yisrael.
What is "Tzvi"?
Rashi: It is beauty - a desired form.
Radak: It is desire, or beauty - "la'Ateres Tzvi" (28:5), "Tzvi Hi l'Chol ha'Aratzos" (Yechezkel 20:6).
What are "Pri ha'Aretz" and what does the verse say about them?
Rashi: They are the children of the Tzadikim - Pri Etz Chayim. They will be the grandeur in which the remnant of Yisrael will glorify themselves.
Radak: Also this refers to Mashi'ach. Initially he will be like a nice sprout; a person is happy to see it. When it becomes fruits, they benefit from it and rejoice more over it. So Melech ha'Mashi'ach - initially people will rejoice over him. When he will defeat Gog in war, and make the land serene, and the entire world will fear him, he will be for grandeur, and [Yisrael] will pride themselves in him over all nations.
Malbim: They are the deeds of the Tzadikim and the fruits (consequences) of their deeds.
What is "Pleitas Yisrael"?
Radak: "Asir mi'Kirbech Alizi Ga'avasech