Surah Al-Kahf 18:21
سُورَةُ الكَهۡفِ · Meccan · Verse 21 of 110
وَكَذَٰلِكَ أَعْثَرْنَا عَلَيْهِمْ لِيَعْلَمُوٓا۟ أَنَّ وَعْدَ ٱللَّهِ حَقٌّۭ وَأَنَّ ٱلسَّاعَةَ لَا رَيْبَ فِيهَآ إِذْ يَتَنَٰزَعُونَ بَيْنَهُمْ أَمْرَهُمْ ۖ فَقَالُوا۟ ٱبْنُوا۟ عَلَيْهِم بُنْيَٰنًۭا ۖ رَّبُّهُمْ أَعْلَمُ بِهِمْ ۚ قَالَ ٱلَّذِينَ غَلَبُوا۟ عَلَىٰٓ أَمْرِهِمْ لَنَتَّخِذَنَّ عَلَيْهِم مَّسْجِدًۭا
Translation
In this way We brought them to people’s attention so that they might know that God’s promise [of resurrection] is true and that there is no doubt about the Last Hour, [though] people argue among themselves. [Some] said, ‘Construct a building over them: their Lord knows best about them.’ Those who prevailed said, ‘We shall build a place of worship over them.’
English translation: M.A.S. Abdel Haleem.
Meaning and reflection
'And thus We made their case known, that people might know God's promise is true and that the Hour is beyond doubt, when they disputed among themselves about their affair.' Ibn Ashur and al-Saadi note the purpose of the whole episode: the sleepers' revival became living proof that resurrection is real, if God can preserve and wake these, He can raise the dead. Yet even then, people fell to disputing over how to memorialise them. Ask yourself: God gave a sign so clear it should have settled the question of the resurrection forever, and people responded by arguing over a monument. It is the recurring human failure: handed a profound truth, we busy ourselves with the trivial around it. When I'm shown something that should reorder my life, do I let it, or do I deflect into secondary debates and management, avoiding the change the sign was meant to demand?
Grounded in classical tafsir: Ibn Ashur, al-Saadi, al-Biqa'i.
Wording
This verse opens a pivotal moment in the story of the Sleepers of the Cave, shifting from their miraculous awakening to their discovery by others. It is Allah speaking directly, describing how He revealed them to the people of that time. The situation is a divine intervention meant to resolve a crucial societal dispute.
The Divine Unveiling
Allah says, "وَكَذَٰلِكَ أَعْثَرْنَا عَلَيْهِمْ" (And thus We made them known). The word "أَعْثَرْنَا" (a'tharnaa) is powerful. As al-Razi explains, its root meaning is "to stumble upon something," which then leads to knowing it. So, Allah uses the cause (stumbling) to describe the effect (knowledge). This implies that the discovery was not a deliberate search but a sudden, unexpected unveiling. It was a sign, not a puzzle to be solved. This sudden revelation served a profound purpose: "لِيَعْلَمُوٓا۟ أَنَّ وَعْدَ ٱللَّهِ حَقٌّۭ وَأَنَّ ٱلسَّاعَةَ لَا رَيْبَ فِيهَآ" (so that they may know that the promise of Allah is true and that the Hour there is no doubt in it). The Sleepers' long slumber and miraculous reawakening were a living proof, making the concept of resurrection tangible for those who doubted.
A Timely Dispute
This unveiling happened "إِذْ يَتَنَٰزَعُونَ بَيْنَهُمْ أَمْرَهُمْ" (when they were disputing among themselves concerning their matter). The word "يَتَنَٰزَعُونَ" (yatanaza'oon), a present tense verb, paints a vivid picture, bringing their contentious debates to life for the reader. They were locked in arguments about the Resurrection and the afterlife itself. Al-Razi offers several possibilities for "أَمْرَهُمْ" (their matter): it could refer to their disagreement about the reality of the Resurrection, or what to do with the Sleepers once discovered, or even the specifics of their story. This dispute made the physical evidence of the Sleepers' reawakening an undeniable sign, directly addressing the core of their contention.
Conflicting Ideas, Firm Resolve
Following the discovery, proposals emerged: "فَقَالُوا۟ ٱبْنُوا۟ عَلَيْهِم بُنْيَٰنًۭا ۖ رَّبُّهُمْ أَعْلَمُ بِهِمْ" (So they said, "Construct over them a structure. Their Lord knows best about them"). This first group suggested simply building a protective structure, perhaps to shield them from visitors, as Ibn Ashur notes. The phrase "رَّبُّهُمْ أَعْلَمُ بِهِمْ" (their Lord knows best about them) could be their humble acknowledgment that they couldn't fully grasp the miracle, or it could be an interjection from Allah, reminding all that ultimate knowledge belongs to Him. Then, the verse describes the powerful group's decision: "قَالَ ٱلَّذِينَ غَلَبُوا۟ عَلَىٰٓ أَمْرِهِمْ لَنَتَّخِذَنَّ عَلَيْهِم مَّسْجِدًۭا" (Those who prevailed in the matter said, "We will surely build a mosque over them"). Ibn Ashur clarifies that "الذين غلبوا على أمرهم" refers to the leaders or people of authority in the city. Their proposal, to build a place of worship, shows a strong, determined resolve, indicated by the emphatic "لَنَتَّخِذَنَّ" (lanattakhithanna). This highlights the shift from mere protection to sanctification, a practice of early nations, though later forbidden in Islam to prevent associating anything with Allah in worship.
Sources: al-Razi (Mafatih al-Ghayb), al-Zamakhshari (al-Kashshaf), Ibn Ashur (al-Tahrir wa al-Tanwir), al-Jadwal fi I'rab al-Quran (Mahmud Safi), al-Jalalayn
Qur'anic Worlds
This verse continues the wondrous account of the People of the Cave, showing how Allah made their story known to a later generation. It's a powerful moment that bridges the past with a crucial lesson for all times.
A Divine Unveiling
Allah tells us, "وَكَذَٰلِكَ أَعْثَرْنَا عَلَيْهِمْ" (And in this way, We made them known). The word *a'tharna* means 'We caused them to be discovered' or 'We made others come across them.' After centuries of sleep, Allah awakened the People of the Cave and, shortly after, caused the people of their time to find them. This wasn't a random event; it had a profound purpose: "لِيَعْلَمُوٓا۟ أَنَّ وَعْدَ ٱللَّهِ حَقٌّۭ وَأَنَّ ٱلسَّاعَةَ لَا رَيْبَ فِيهَآ" (so that they would know that Allah's promise is true and that the Hour is coming, without doubt).
As scholars like Ibn Kathir and Mufti Shafi' explain, the society at the time of the discovery was divided, with many doubting the physical resurrection of bodies. This miraculous re-emergence of the Cave Dwellers after such a long time served as irrefutable proof of Allah's power to bring the dead back to life. It was a tangible sign, demonstrating that just as Allah preserved these bodies in sleep for centuries and then revived them, He is perfectly capable of resurrecting all of humanity on the Day of Judgment. This event was a direct answer to a pressing spiritual question of that age, settling disputes about the reality of the Hereafter.
Echoes from Past Nations
The verse then describes the reactions of the people who discovered them: "إِذْ يَتَنَازَعُونَ بَيْنَهُمْ أَمْرَهُمْ" (as they disputed among themselves about their affair). Al-Razi and al-Baghawi point out that these debates covered various aspects, including the nature of resurrection itself and what to do with the Cave Dwellers after their eventual death.
Some said, "ٱبْنُوا۟ عَلَيْهِم بُنْيَانًۭا ۖ رَّبُّهُمْ أَعْلَمُ بِهِمْ" (Build a structure over them; their Lord knows best about them), a cautious approach acknowledging the mystery. However, "قَالَ ٱلَّذِينَ غَلَبُوا۟ عَلَىٰٓ أَمْرِهِمْ لَنَتَّخِذَنَّ عَلَيْهِم مَّسْجِدًۭا" (those who prevailed in their affair said, 'We will surely build a place of worship over them'). This highlights a practice common among previous nations, where individuals of influence decided to build mosques or places of worship over the graves of the righteous. The plain meaning of the verse (Ayah Context) and scholars like Sayyid Qutb and Ibn Kathir strongly note that our Prophet Muhammad (peace be upon him) explicitly warned against this practice, condemning those who turn graves of prophets and righteous people into places of worship. This reflects a recurring human tendency to venerate individuals in ways that can lead to misguidance, diverting from pure worship of Allah alone.
This part of the story, set in the "Worlds of Past Nations," serves as a timeless lesson for us, guiding us on how to approach reverence for the pious and reminding us to safeguard the purity of our worship.
Sources: al-Razi (Mafatih al-Ghayb), al-Baghawi (Maalim al-Tanzil), Sayyid Qutb (Fi Zilal al-Quran), Ma'arif al-Quran (Mufti Shafi), al-Tabari (Jami al-Bayan), Ibn Kathir
Topics that discuss this verse
Surah Al-Kahf 18:21 is discussed in 3 study guides on Maani. Each guide gathers the key verses, Arabic words and lessons of one Quranic topic.
Reflect on this verse
Open Surah Al-Kahf 18:21 in Maani to reflect on it through the Five Lenses: its wording, its context, what it means for you, its connections across the Quran and its lessons, grounded in classical tafsir.