He sends down rain from the sky, causing the valleys to flow, each according to its capacity. The currents then carry along rising foam, similar to the slag produced from metal that people melt in the fire for ornaments or tools. This is how Allah compares truth to falsehood. The ˹worthless˺ scum is then cast away, but what benefits people remains on the earth. This is how Allah sets forth parables.

He sends down water (rain) from the sky, and the valleys flow according to their measure, but the flood bears away the foam that mounts up to the surface - and (also) from that (ore) which they heat in the fire in order to make ornaments or utensils, rises a foam like unto it, thus does Allâh (by parables) show forth truth and falsehood¹. Then, as for the foam it passes away as scum upon the banks, while that which is for the good of mankind remains in the earth. Thus Allâh sets forth parables (for the truth and falsehood, i.e. Belief and disbelief).