John Calvin Commentary Hosea 1:5

"And it shall come to pass at that day, that I will break the bow of Israel in the valley of Jezreel." — Hosea 1:5 (ASV)

This verse was intentionally added; for the Israelites were so inflated with their present good fortune that they laughed at the judgment denounced. They indeed knew that they were well supplied with arms, men, and money; in short, they thought themselves in every way unassailable. Therefore, the Prophet declares that all this could not prevent God from punishing them.

“You are,” he says, “inflated with pride; you set up your valor against God, thinking yourselves strong in arms and in power; and because you are military men, you think that God can do nothing. And yet your bows cannot restrain his hand from destroying you. But when he says, I will break the bow, he mentions a part for the whole, for under one kind he includes every kind of arms. But as for what the Prophet had in view, we see that his only object was to break down their false confidence. For the Israelites thought that they would not be exposed to the destruction which Hosea had predicted, because they were dazzled with their own power and thought themselves beyond the reach of any danger, while they were so well fortified on every side. Therefore, the Prophet says that all their fortresses would be nothing against God; for in that day, when the ripe time for vengeance shall come, the Lord will break all their bows, he will tear in pieces all their arms, and reduce their power to nothing.

We are warned here always to take heed, lest anything lead us into a torpid state when God threatens us. Though we may have strength, though fortune (so to speak) may smile on us, though, in a word, the whole world should combine to secure our safety, yet there is no reason why we should congratulate ourselves when God declares himself opposed to us and angry with us. Why? Because, just as he can preserve us when unarmed whenever he pleases, so he can also strip us of all our arms and reduce our power to nothing. Let this verse then come to our minds whenever God terrifies us with his threats; and what it teaches us is that he can take away all the defenses in which we vainly trust.

Now, as Jezreel was the capital of the kingdom, the Prophet distinctly mentions the place, I will break in pieces the bow of Israel in the valley of Jezreel; that is, the Lord sees what kind of fortress there is in Samaria, in Jezreel, but he will make an end of you there, in the very midst of the land. You think that you have a place of safety and a firm position there, but the Lord will bring you to nothing, even in the valley of Jezreel.