Does "inscrutable" refer to intangible things or tangible things?

[DONALD P]

Inscrutable describes a good poker player's face, it gives nothing away as to what he is thinking.

The inscrutable face of the Buddha is a term in use.

Difficult to understand is incomprehensible.

I can't read your handwriting because it is illegible, not inscrutable.

[i like pie]

Like, does it mostly refer to the meaning of a passage as difficult to understand?

Or does it refer usually to the handwriting of a person as difficult to understand?

Or can it do both? BUT PLEASE INCLUDE WHICH TYPE IS USED MORE OFTEN!!!

Thanks in advance!