Surah Ar-Ra'd (The Thunder), Verse 17

اَنْزَلَ مِنَ السَّمَآءِ مَآءً فَسَالَتْ اَوْدِیَةٌ بِقَدَرِهَا فَاحْتَمَلَ السَّیْلُ زَبَدًا رَّابِیًا وَمِمَّا یُوْقِدُوْنَ عَلَیْهِ فِی النَّارِ ابْتِغَآءَ حِلْیَةٍ اَوْ مَتَاعٍ زَبَدٌ مِّثْلُهٗ كَذٰلِكَ یَضْرِبُ اللّٰهُ الْحَقَّ وَالْبَاطِلَ فَاَمَّا الزَّبَدُ فَیَذْهَبُ جُفَآءً وَاَمَّا مَا یَنْفَعُ النَّاسَ فَیَمْكُثُ فِی الْاَرْضِ كَذٰلِكَ یَضْرِبُ اللّٰهُ الْاَمْثَالَ ۟

Anzala minas samaaa'i maaa'an fasaalat awdiyatum biqadarihaa fahtamalas sailu zabadar raabiyaa; wa mimmmaa yooqidoona 'alaihi fin naarib tighaaa'a bilyatin aw mataa'in zabadum misluh; kazaalika yadribul laahul haqqa wal baatil; fa ammaz zabadu fa yazhabu jufaaa'aa; wa ammaa maa yanfa'un naasa fa yamkusu fil ard; kazaalika yadribul laahul amsaal

“He sends down water From the skies, and the channels Flow, each according to its measure : But the torrent bears away The foam that mounts up To the surface. Even so, From that (ore) which they heat In the fire, to make ornaments Or utensils therewith, There is a scum likewise. Thus doth Allah (by parables) Show forth Truth and Vanity. For the scum disappears Like froth cast out ; While that which is for the good Of mankind remains On the earth. Thus doth Allah Set forth parables.”

Quran 13:17 (Yusuf Ali Translation)