2 Tried often to the scathe of many dear,
Tried > Tested [in his prowess] scathe > harm, damage dear > grievously
3 That none in equal arms him match might,
That > [Such that; so that] equal arms > impartial combat might > could
4 Which, his mother seeing, began to fear
began > [she began]
5 Lest his too haughty hardiness might rear
haughty > high; proud, arrogant rear > arouse, bring into existence
6 Some hard mishap, in hazard of his life: 7 For-thy she oft him counselled to forbear
For-thy > For this reason