After 20 years of oppression from a Canaanite king, Jabin of Hazor, the Israelites ‘cried out to the Lord’ for help. Why it took 20 years, we don’t know. Perhaps it was the time needed for the next generation of men to come of age and join what we would probably now call a resistance army. Perhaps there was another reason.
Whatever the reason, once Israel asked for help, God delivered. A meagre army of 10,000 men with no spears or shields was given victory over the entire might of King Jabin’s army with its 900 iron chariots and all of his warriors, led by Sisera. The agent was simply God throwing ‘Sisera and all his chariots and warriors into a panic’: the army was totally destroyed:
5:20 The stars fought from heaven.
The stars in their orbits fought against Sisera.
The Kishon River swept them away—
that ancient torrent, the Kishon.
The Kishon River isn’t much to look at unless it rains: it certainly isn’t a torrent. But with enough rain, the river floods and the plain around it can get really boggy—not the best conditions for driving iron chariots. Small wonder, then, that Sisera abandoned his chariot and tried to escape on foot (to be caught and killed).