Radak: This corresponds to "Tik'u Shofar b'Tziyon" (15).

Malbim #1: Bnei Tziyon do not rejoice over temporary success, only in Hashem, that Hashem returned to be pleased with you, because you repented. You rejoice that he sent locusts and hunger, for they forced you to repent.

Malbim #2: If rain does not fall in Cheshvan, the Tzibur fasts Monday, Thursday and Monday, and another three, and another seven fasts. After this, rain does not help so much, so only individuals fast. Bnei Tziyon fasted until Nisan, and the rain came then, and was good for trees and grain, even though it is not the proper time for rain.

Rashi: Your Nevi'im, who are Moreh (instruct) you to return to Me, to be Metzadek (justify) you.

Radak: Moreh is like Yoreh (the first rainfall). He gave it to you for Tzedakah - He passed over your sins, and gave rain.

Radak citing Targum Yonasan: One who teaches to you for merit.

Malbim: The locusts, which teach you to do Mitzvos Bein Adam la'Makom.

Rashi: This is like "Yoreh u'Malkosh" (Devarim 11:14). Rishon is Nisan. Even though Yoreh is the first rainfall that comes on the seeds, which is in Cheshvan, that year it was in Nisan, like it says in Ta'anis (5a); grain that normally grows in six months, grew in 11 days ¹ . Radak - the first rain was on Nisan 1. The Navi told them to seed. They said, one who has [only] a Kav (small amount) of wheat or barley, should he eat it and live (a short time), or seed it and die?! He said, even so, seed! A miracle occurred, and was revealed to them [grain] in ant-holes and cracks in walls. They seeded on the second, third and fourth of the month, and the second rainfall came on the fifth. They offered the Omer on the 16th. It says about that generation "ha'Zor'im b'Dim'ah b'Rinah Yiktzoru" (Tehilim 126:5).

Radak #1: First it mentioned Yoreh, which is in Cheshvan, and afterwards explained "Geshem Moreh u'Malkosh ba'Rishon."

Radak #2: Moreh came in its time - Cheshvan, and also Malkosh was in its time - Nisan.