Does a bird land in a snare where no bait has been set? Does a trap spring from the ground when it has nothing to catch?
The third similitude now follows, Will a bird fall on the earth, he says, without a fowler? The Prophet means here that nothing happens without being foreseen by God; for as nets are laid for birds, so God ensnares men by his hidden punishments.
The scope of these verses is to convince the people of Israel that God had a controversy with them. That which the prophet has to say to them is to let them know that the Lord has something to say against them, Amo 3:1.
Commenting on Amos 3:1-8
Shall a trumpet be blown in the city,.... Meaning not any trumpet blown, as the silver trumpet for the gathering of the people to worship, or the jubilee trumpet, which proclaimed liberty to them, or any other, expressive of joy and gladness; but the sound of the trumpet, the alarm of war, or what is blown by the watchmen on the walls, descrying an enemy...