of > after
3 And in a rocky cave, as wight forlorn,
wight > person, so: child forlorn > abandoned, deserted
4 Long time she fostered up, till he became
fostered up > brought up [with parental care]
5 A mighty man at arms, and mickle fame
mickle > much
6 Did get through great adventures by him done: 7 For never man he suffered by that same
suffered > permitted
8 Rich Strand to travel, where he did won,