أَنزَلَ مِنَ ٱلسَّمَآءِ مَآءً فَسَالَتْ أَوْدِيَةٌۢ بِقَدَرِهَا فَٱحْتَمَلَ ٱلسَّيْلُ زَبَدًا رَّابِيًا … كَذَٰلِكَ يَضْرِبُ ٱللَّهُ ٱلْحَقَّ وَٱلْبَٰطِلَ فَأَمَّا ٱلزَّبَدُ فَيَذْهَبُ جُفَآءً وَأَمَّا مَا يَنفَعُ ٱلنَّاسَ فَيَمْكُثُ فِى ٱلْأَرْضِ
"He sent down water from the sky, and the valleys flowed each according to its own measure; and the torrent carried a swelling scum… Thus does God set forth the true and the false: the scum is cast off and goes; what benefits people stays in the earth."
The verse sets up two separate comparisons: the scum of the torrent and the dross of metal (wa mimmā yūqidūna ʿalayhi fi'n-nāri'btighāʾa ḥilyatin aw matāʿin zabadun mithluh).
| Element | The scum | What remains |
|---|---|---|
| Position | On top — rābiyan | Below / in the earth |
| Visibility | What is seen | What is not seen |
| Duration | Yadhhabu jufāʾan — it is cast off and goes | Yamkuthu fi'l-arḍ — it stays |
| Measure | — | Mā yanfaʿu'n-nās — benefit |
I record this as my own reading, and its ground is the elements of the similitude: the verse separates the true from the false not by momentary visibility but by what lasts. And the measure set down is mā yanfaʿu'n-nās (what benefits people) — the distinction, that is, lies not in the claim itself but in what it leaves behind.
This detail is worth recording: the water is one, the valleys different. And this is the same observation as that of the fourth verse: a single water, a different yield. It is a repetition that can be verified within the sūra.
The similitude of water, plant and withering was treated at al-Kahf 18/45 and al-Zumar 39/21; what sets al-Raʿd apart is that its subject is not the water itself but the scum the water carries.