He sent down water from the sky, so valleys flowed according to their measure, therefore the water flow brought forth the froth swollen upon it; and upon which they ignite the fire, to make ornaments and tools, from that too rises a similar froth; Allah illustrates that this is the example of the truth and the falsehood; the froth then bursts and disappears; and that which is of use to people, remains in the earth; this is how Allah illustrates the examples.