Surah At-Tur (The Mount Tur), Verse 38

اَمْ لَهُمْ سُلَّمٌ یَّسْتَمِعُوْنَ فِیْهِ فَلْیَاْتِ مُسْتَمِعُهُمْ بِسُلْطٰنٍ مُّبِیْنٍ ۟

Am lahum sullamuny yastami'oona feehi falyaati mustami'uhum bisultaanim mubeen

“Or have they a ladder, by which they can (climb up to heaven and) listen (to its secrets)? Then let (such a) listener of theirs produce a manifest proof.”

Quran 52:38 (Yusuf Ali Translation)