1 Kings 20:10 - Albert Barnes' Notes on the Bible

If the dust of Samaria shall suffice for handfuls ... - In its general sense this phrase is undoubtedly a boast that the number of Ben-hadad’s troops was such as to make resistance vain and foolish. We may parallel it with the saying of the Trachinian at Thermopylae, that the Persian arrows would darken the light of the sun. Probably the exact meaning is, “When your town is reduced to ruins, as it will be if you resist, the entire heap will not suffice to furnish a handful of dust to each soldier of my army, so many are they.” There was a threat in the message as well as a boast.