Watchman, what of the night?

From HunterWiki

I have recently stumbled across the following pair of verses:

He calls to me out of Seir,

Watchman, what of the night?
Watchman, what of the night?

The watchman said,

"The morning comes, and also the night.
If you will inquire, inquire;
Return! Come back!"

and I find them very eerie and portentous, a sense of something big coming. But ultimately, I have no idea what they mean!