4 Dismay with fear, or cause on foot to fly,

on > (See Textual Appendix) fly > flee

5 But either hellish fiends, or powers on high:

But > Unless [it be]

6 Which was the cause, when erst that horn I heard,

erst > first

7 Weening it had been thunder in the sky,

Weening > Supposing, believing

8 I hid myself from it, as one afeard;

afeard > frightened