How can one respond to those who question devils ascending to heaven to eavesdrop, given the immense distance between the earth and heaven, and that a devil’s speed is less than the speed of light?

The "sky" from which devils eavesdrop is not the built sky, but rather clouds and similar formations that surround the earth. Angels descend to the clouds to mention what has been decreed in the heavens, and devils eavesdrop and then relay it to soothsayers.

The meteors with which devils are pelted appear at an altitude of 60 miles and disappear at 40 miles. There is nothing in the verses or hadiths to prevent reaching the planets, for the word "sky" refers to everything that is high and elevated, and the planets are in an orbit between the sky and the earth. The built heavens are preserved with their gates and guards, and devils cannot enter them. We believe in the devils' eavesdropping at the boundaries of revelation, without delving into the specifics of how this occurs.