Answer:
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?
I grow where no flower grows, where no light touches the walls, up or down, that I don't care, was here before people were.
It's in your hand though you can not feel it. Only you and time can reveal it.
Sleeping during the day, I hide away. Watchful through the night, I open at dawn's light. But only for the briefest time, do I shine. And then I hide away. And sleep through the day.
Both punishment and sweet reward, It will befall both fool and lord. It is a spiritual scoreboard, Your every deed it does record.
What language does a billboard speak?