Rashi on Joel
the teacher for justification Heb. מוֹרֶה. Your prophets who teach you to return to Me, in order to justify you.
Ibn Ezra on Joel
And the children: Yefet [ben Ali] said that the instructor (hamoreh) is the prophet that instructs them about the righteous path. And that is why good is coming to them. And it mentioned early rain (moreh) and late rain, as [in] (Judges 15:16), "With the jaw of an ass (chamor), mass (chamor) upon mass"...
Rashi on Joel
the early rain and the late rain. Heb. מוֹרֶה, like (Deut. 11:14) “the early rain (יוֹרֶה) and the late rain (וּמַלְקוֹֹש).”