Yes, it is a marvelous quote paraphrased from the Qur'an. Please remember it. With a Moroccan background born and living in Denmark, your English is excellent, Ma-Sha-Allah.
13:17 He sends down water from the height causing the riverbeds to flow according to their measure and the flood bears on its surface swelling foam. When they use fire to refine metals for their jewelry or equipment, foam is produced like it. In this way, God is citing for you the example of the truth and falsehood. For, as far as the foam is concerned, it passes away as scum upon the riverbanks - While that which is of benefit to mankind, exists on earth. This is how God uses analogies for you to understand. [The real existence on earth is of the person or the system that benefits humanity]