Key takeaway
The Quran calls mountains awtād ("stakes" or "pegs," 78:7) and rawāsī ("firmly set" things) placed "lest it shift with you" (16:15, 21:31). Geology confirms that large mountain ranges have deep roots of crust extending far below them, like a peg driven into the ground. This principle, isostasy, was described in the 1850s. Whether mountains "stabilize" the Earth in a broader sense is debated.
The verses
أَلَمْ نَجْعَلِ ٱلْأَرْضَ مِهَـٰدًا ٦ وَٱلْجِبَالَ أَوْتَادًا ٧
6 Have We not made the earth a resting place? 7 And the mountains as stakes?
وَأَلْقَىٰ فِى ٱلْأَرْضِ رَوَٰسِىَ أَن تَمِيدَ بِكُمْ وَأَنْهَـٰرًا وَسُبُلًا لَّعَلَّكُمْ تَهْتَدُونَ ١٥
And He has cast into the earth firmly set mountains, lest it shift with you, and [made] rivers and roads, that you may be guided,
وَجَعَلْنَا فِى ٱلْأَرْضِ رَوَٰسِىَ أَن تَمِيدَ بِهِمْ وَجَعَلْنَا فِيهَا فِجَاجًا سُبُلًا لَّعَلَّهُمْ يَهْتَدُونَ ٣١
And We placed within the earth firmly set mountains, lest it should shift with them, and We made therein [mountain] passes [as] roads that they might be guided.
وَٱلْجِبَالَ أَرْسَىٰهَا ٣٢
And the mountains He set firmly
Key Arabic terms
| Arabic | Transliteration | Meaning |
|---|---|---|
| أَوْتَادًا | awtād | stakes or pegs, like those that hold a tent in place, with most of their length in the ground |
| رَوَٰسِىَ | rawāsī | firmly anchored things (from rasā, to be firm or anchored, like a ship at anchor) |
| أَن تَمِيدَ بِكُمْ | an tamīda bikum | "lest it sway or shift with you" |
Roots beneath mountains
In 1855 George Airy and John Pratt proposed explanations for surveys in India showing that the Himalayas exert less gravitational pull than their visible mass would suggest. Airy's explanation, now part of the theory of isostasy, is that mountains are supported by thick roots of lighter crust that extend deep into the denser mantle, much as an iceberg floats with most of its bulk below water. Under major ranges the crust can be roughly 70 km thick, about twice the continental average. The image of a stake with a hidden length beneath the surface is therefore apt.
"Lest it shift with you"
Classical commentators understood 16:15 to mean that Allah made the earth a steady, settled place for people to live, with mountains as part of that steadiness. Some modern writers argue that mountains help stabilize the crust. Geologists would add that mountains are themselves products of tectonic forces, built where plates collide, and those regions often have frequent earthquakes.
Balanced assessment
Moderate A reasonable, accurate correspondence; the words have other valid meanings or the fact was partly known before.
The "peg" description fits the established fact of mountain roots very well, and the Quran's word choice is precise. Claims that mountains prevent earthquakes are not supported by geology and should not be made. The verse is better read as describing a stable, habitable earth whose mountains are deeply anchored, without implying that tectonic motion stops.
Frequently asked questions
Why does the Quran call mountains pegs?
Quran 78:7 calls mountains awtād, or stakes. Geology shows that major mountains have deep crustal roots extending far below the surface, like a peg driven into the ground.
Do mountains stop earthquakes?
No. Mountain ranges form where tectonic plates collide, and such regions often have earthquakes. The Quran describes mountains as firmly set and the earth as a steady dwelling. It does not claim earthquakes never happen.
References
Quran
- Quran 78:6–7, Saheeh International translation (Quran.com)
- Quran 16:15, Saheeh International translation (Quran.com)
- Quran 21:31, Saheeh International translation (Quran.com)
- Quran 79:32, Saheeh International translation (Quran.com)
Science & history
Classical exegesis is summarized from the standard commentaries (e.g. al-Ṭabarī, Ibn Kathīr, al-Qurṭubī). See our methodology.
Cite this page
Quran Scientific Miracles. “Mountains as Pegs.” https://quranscientificmiracles.com/topics/mountains-as-pegs/ (reviewed 2026-10-20).