Analysis of The Hidden Room

I marvel if my heart,
Hath any room apart,
Built secretly its mystic walls within;
With subtly warded key.
Ne'er yielded unto me--
Where even I have surely never been.

Ah, surely I know all
The bright and cheerful hall
With the fire ever red upon its hearth;
My friends dwell with me there,
Nor comes the step of Care
To sadden down its music and its mirth.

Full well I know as mine,
The little cloister'd shrine
No foot but mine alone hath ever trod;
There come the shining wings--
The face of one who brings
The pray'rs of men before the throne of God.

And many know full well,
The busy, busy cell,
Where I toil at the work I have to do,
Nor is the portal fast,
Where stand phantoms of the past,
Or grow the bitter plants of darksome rue.

I know the dainty spot
(Ah, who doth know it not?)
Where pure young Love his lily-cradle made;
And nestled some sweet springs
With lily-spangled wings--
Forget-me-nots upon his bier I laid.

Yet marvel I, my soul,
Know I thy very whole,
Or dost thou hide a chamber still from me?
Is it built upon the wall?
Is it spacious? is it small?
Is it God, or man, or I who holds the key?