At-Tur (The Mount)

38. Or have they a stairway [leading to heaven] by means of which they listen [to secrets of the heavens]? If it is true, then their listeners should produce evident arguments.

The blessed Verse in question is asking if they have access to some stairway through which they may ascend to heaven and thereby attain to knowledge concerning the higher world and its angels and sacred intellects. If it is true, it is incumbent upon them to produce evident arguments as to what they have heard and learned.

It may intend to say that such people who have not transcended beyond the world of nature and are unaware of the metaphysical world but are immersed in the mire of nature may not claim to have availed themselves of intellect and perfection and attribute baseless accusations as to madness and sorcery to the Noble Prophet of Islam (S) whose Noble Spirit is conjoined with the metaphysical world since he possesses the supreme intellect and is the first being to be created by God Almighty.

If these disbelievers are aware of the higher world, they are supposed to produce arguments and substantiate their claims in the same manner that Prophets produced arguments in order to substantiate their statements.