At-Tur 52:38

Am lahum sullamun yastamiAAoona feehifalya/ti mustamiAAuhum bisultanin mubeen

Or have they a stairway [into the heaven] upon which they listen? Then let their listener produce a clear authority [i.e., proof].

Or have they a stairway (to the heavens) by means of which they listen (to the divine decrees)? If so, their listener must bring a clear proof.