Analysis of The Guest House

What imps are these that come with scowl and leer?
Black motes upon the morning's amber beam,
They crowd and float about each happy dream
And blow upon pure joy the taint of fear.
Perforce those muttered hideous words we hear,
Yet bid our nobler nature rise supreme
And, sunlike, dry to naught th' infernal steam
Till all our day is luminous and clear.
“What cruel beasts find refuge in the soul
Amid the murky deep of sightless flame
Whose waves are flatten'd by a rain of blood!”
Nay, but however pure the waters roll,
The offal thrown therein will rise and shame
Their glittering pride with bubbles from the mud.