Why does it say "Asher l'Veis Hashem"?
Radak: This is like b'Veis Hashem. Targum Yonasan is 'who serve in the Beis ha'Mikdash of Hashem.'
To which Nevi'im did they ask?
Radak: To Chagai, Zecharyah and Malachi.
Radak citing Targum Yonasan: They asked Safraya 1 .
Often, the Targum of Nevi'im is Safraya! (PF)
Why was this a question?
Radak: They still did not believe that Bayis Sheni would be built, due to enemies who stopped the building many years ago. Even though they heard that they started building again, they had little Emunah. They did not want to ascend from Bavel, for they did not believe that the Bayis would be finished and stand, due to their oppressors.
Malbim citing Mahari: Bayis Sheni was small in their eyes for seven reasons. (a) They saw that the Shechinah did not return to dwell in it like in Bayis Rishon. Five matters of Bayis Rishon were not in Bayis Sheni (refer to 4:9:1:2*). (b) It was under the rule of the kings of Paras - they feared lest they expel them from the land again. (c) There was not a total gathering of the exiles. Those cast off to the four corners of the world did not return. (d) They saw that the land was cursed. This showed that Hashgachah was not there like initially. (e) They were plundered and disgraced among the nations. (f) They saw that the Kusim occupied a large part of the land, and few exiles returned. (g) They saw that they do not have a man from Beis David ruling over them.
Why did they ask only about Tish'ah b'Av?
Malbim: There was no question about Tzom Gedalyah 1 . It was due to the destruction of the settlement that Nevuzaradan left in the land of Aniyim for "Chormim v'Yogvim" (Yirmeyah 52:16; refer to Yirmeyah 52:16:2:1-2, 52:16:3:1-3). Due to the murder of Gedalyah, they fled. Now Jews returned to the land like the number that were with Gedalyah, so there is no reason to fast. They were unsure about the three fasts due to Churban ha'Ir. They asked about Tish'ah b'Av - if they need not fast on it, all the more so on the others (Asarah b'Teves and Shiv'ah Asar b'Tamuz). They asked now, on the fourth of Kislev, to know how to conduct on Asarah b'Teves (five weeks later).
Below (5), Hashem answered about Tzom ha'Shevi'i, i.e. Tzom Gedalyah! (PF)
Why does it say "Hinazer"?
Rashi, Targum Yonasan: It is to separate from pleasure. Nezirah is always separation.
Radak: Should I refrain from eating, drinking and pleasure?
Malbim: This is prayer and supplication for the future. They wanted to know both about fasting, and crying over the past. Hinazer is Makor (infinitive).
