Do we know what Hashem answered the angel?
Rashi: No ? also Zecharyah did not hear it! However, since the angel told him "Kra Leimor? Kineisi?.", we know that He answered good words.
Radak (14): Yes ? it is what the angel told Zecharyah to announce ? "Kineisi?" (14).
Malbim: Zecharyah knew, but he did not reveal it, for Hashem did not command him to do so.
What are "Devarim Nichumim"?
Radak #1: The word Samuch to Nichumim is omitted. It should say Devarim Divrei Nichumim.
Radak #2: Nichumim is an adjective (words of consolation). This Perush is primary.
Malbim: Hashem informed the angel that the length of the Galus and the afflictions are for the good of Yisrael. They will turn into great consolations, and there will be a general Ge'ulah and eastern Tzedek.