If you could ask Ra any one question, what would you ask?

[anagogy]

Isn't light the food of 6th density, not 5th density? This would mean that 6D is the density of resting. I thought it was 5D before.

When Ra referred to the "density of resting" they were only calling it that because that is where Carla's spirit would rest when Ra was channelled.  Her mind/body/spirit complex would leave the shell of yellow ray, and Ra would enter and speak.  While they spoke, her spirit rested in its native density.  Thus, it is not that a specific density is designated the "density of resting".  Any density can be a place of rest and rejuvenation, even our 3rd density physical environment (you do rest don't you? Though judging by your posts timestamp, not at night haha).