Or have they a ladder by which they could [ascend to ultimate truths and] listen [to what is beyond the reach of human perception]? Let, then, any of them who have listened [to it] produce a manifest proof [of his knowledge]!

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.

Or have they any stairway (unto heaven) by means of which they overhear (decrees). Then let their listener produce some warrant manifest!

Or have they the means by which they listen? Then let their listener bring a clear authority.

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