Surah 15. Al-Hijr, Ayah 8

Sc., "and not just to satisfy a frivolous demand of people who refuse to consider a prophetic message on its merits". Moreover - as is evident from the next clause - an actual appearance of the angels to ordinary men would but presage the Day of Judgment (described in 78:39 as "the Day of Ultimate Truth") and, thus, the doom of the deniers of the truth spoken of here.

Cf. 6:8 - "had We sent down an angel, all would indeed have been decided", i.e., the Day of Judgment would have come.

Angels are not sent down to satisfy the whim or curiosity of the unbelievers. They are sent to bring inspiration to Allah's messengers and to execute Allah's decrees.

If the angels were to appear before the ungodly, it would mean that they came to execute just punishment, and then there would be no hope of respite possible for the ungodly.