to break through: force a way through a barrier so that what was held back bursts out the other side
Every use of this word turns on one picture: a boundary that gives way and whatever it held back rushing through. The boundary can be a literal stone wall, a hedge around a vineyard, or a city's defenses, and the action is tearing it open or knocking it down.
From that picture the word spreads in several directions. When God is the one who breaks through, the image becomes an outburst of anger or judgment that suddenly bursts loose against people, the way a dam gives way and the flood pours out. When a flock, a family, or a nation is the subject, the same force runs the opposite way: they overflow their old limits and spread out and multiply across the land. The word can also describe pressing hard against someone's resistance until it gives, or people breaking loose from the restraints meant to hold them.
What ties these together is not a vague family resemblance but a single motion seen from different sides: a limit is overpowered and something pours past it. The reader who keeps the dam-and-flood image in mind will recognize the same word at work whether a wall is falling, a people is growing, or God's wrath is breaking loose.