In this section of the chapter, the events described have moved on from the previous verses towards the demise of the northern kingdom of Israel. Now there is the additional danger of war, first along with her southern neighbour Judah (vv. 8 and 10), but secondly and ominously the threat posed by Assyria (v. 13).
Verse 8, with its references to the blowing of musical instruments, describes a call to various locations to prepare for war. The places mentioned belonged to the tribe of Benjamin, which was part of the southern kingdom of Judah. It is not clear if this is a call to defend their territory or to get involved in attacking an opponent.
Both Israel (Ephraim) and Judah will be defeated (vv. 9-11). God reveals that the main cause of the defeat will be himself, because he will punish his people for their sins. Hosea mentions one major sin of the leaders of Judah, which was to ignore and treat with disdain divisions between territories (whether tribal divisions or family divisions) that had been decided when Israel came into the Promised Land centuries before. In other words, they were rebelling against the Lord’s method of dividing the land, and for this sin they would experience his wrath. The prophet also mentions the sin of the northern kingdom, idolatry, which he graphically describes as ‘filth’.
God then depicts himself in an unexpected manner when he likens himself to a moth and to dry rot (v. 12). The point of both illustrations is that they are prolonged in their effect. A moth starts destroying a garment and persists until it is gone, and dry rot works similarly in a building. The Lord is saying that once he begins his work of judgement he will persevere with it.
In verse 13, Hosea mentions the response of Israel to her political weakness (in the ESV he does not mention what Judah did in response) – instead of trusting in the Lord she went to the ruler of Assyria for help (such an action would only have told Assyria that Israel would be easily defeated). Israel’s action here is a picture of everyone who tries to sort out their problems without the Lord’s help. Such remedies never work.
The Lord’s response to both Israel and Judah is to become more aggressive (v. 14). He changes the illustration to a young lion (rather than being like a moth or dry rot) destroying and carrying away its prey. The outcome will be exile (the Lord will carry them away and none will rescue them from their punishment).
The period of punishment will last until the people repent and return to the Lord (v. 15). Hosea does not say how long that would be. But he does describe repentance, and as we can see, it is not like a calm period of spiritual reflection. Instead it is full of spiritual energy and strong emotion as those repenting confess their sins. It involves earnestly seeking the Lord who has hidden himself, and in repentance they will keep seeking until they sense his face is again turned towards them in grace. I wonder if our repentance is like that.