You must not stay sleeping and dallying there in the house,
though you built it, or though it has been built for you.
out of the dark confinement! out from behind the screen!

in this passage, the "house" is a symbol for
- freedom
- the road
- imprisonment
- the universe

Imprisonment

Explanation:

In these lines, we can see that the concept of a house is being used as a symbol to represent imprisonment. We know this because the passage compares the house to a "dark confinement," and to be confined is to be imprisoned. Moreover, the speaker urges the reader to get out from it and experience the world, regardless of what the comforts of the house are.