Al-Kahf 18:97

<h2>The Barrier restrains Them, but It will be breached when the Hour draws nigh</h2><p>Allah tells us that Ya'juj and Ma'juj could not climb over the barrier or penetrate its lower portion. Varying forms of the verb are used here in the Arabic text to reflect the difficulty of the action referred to.</p><div class="arabic uthmani">فَمَا اسْطَـعُواْ أَن يَظْهَرُوهُ وَمَا اسْتَطَـعُواْ لَهُ نَقْبًا </div><p>(So they (Ya'juj and Ma'juj) could not scale it or dig through it.) This indicates that they could not penetrate it or dig through it. Imam Ahmad recorded that Zaynab bint Jahsh, the wife of the Prophet said, "The Prophet woke from sleep, and he was red in the face. He said,</p><div class="arabic uthmani">«لَا إِلَهَ إِلَّا اللهُ وَيْلٌ لِلْعَرَبِ مِنْ شَرَ قَدِ اقْتَرَبَ فُتِحَ الْيَوْمَ مِنْ رَدْمِ يَأْجُوجَ وَمَأْجُوجَ مِثْلُ هَذَا»</div><p>(La ilaha illallah! Woe to the Arabs from the evil that has approached (them). Today a hole has been opened in the barrier of Ya'juj and Ma'juj like this.) and he made a circle with his index finger and thumb. I Zaynab said, `O Messenger of Allah, will we be destroyed even though there will be righteous people among us' He said:</p><div class="arabic uthmani">«نَعَمْ إِذَا كَثُرَ الْخَبَث»</div><p>(Yes, if evil …

And (Gog and Magog) were not able to surmount, nor could they pierce (it).

Thus were they made powerless to scale it or to dig through it.

So they [Ya'juj and Ma'juj (Gog and Magog)] were made powerless to scale it or dig through it.

So they were unable to climb it, and they could not penetrate it.