[QHdy5Z3A]

It's a glowing light that comes from the purifying of the soul such that it gives the spirit (which is rooted in the heart and flows in the blood) a glow, like the moon at night or like olive oil).

That's clearly what "abyadhat wujuhum" "their faces will be white" and "wujuhun yawmadhin na'imah" "faces that day will be beaming" etc. and on the flip side "aswadat wujuhuhum" "their faces will be blackened" referring to the disbelievers.

The spirit can shine through the flesh and blood and produce that glowing that comes purely from faith and strengthens when people perfect their souls like the sufis etc.

I speak on this based on first hand experience.

Spirits are either angels or demons. Ibn 'Abbas clearly new the meaning of the hadith that angels were created from light and jinn from nar samum.

Fire is where light comes from. The hotter the fire the brighter the light, and the less hot, the closer it is to the kind of black smoke that you see emanating off a barbeque grill or incence. The shayatin from the jinn look like smoke, literally in their most common, slightly visible form, or like heat vapors in some cases (obviously they can take other forms, but this is most common from what I've read from exorcists and from my own experience).