Analysis of The Way I read a Letter's—this

The Way I read a Letter's—this—
'Tis first—I lock the Door—
And push it with my fingers—next—
For transport it be sure—

And then I go the furthest off
To counteract a knock—
Then draw my little Letter forth
And slowly pick the lock—

Then—glancing narrow, at the Wall—
And narrow at the floor
For firm Conviction of a Mouse
Not exorcised before—

Peruse how infinite I am
To no one that You—know—
And sigh for lack of Heaven—but not
The Heaven God bestow—