that > [that which]
3 And brought through points of many perilous swords: 4 But if you list to see your courser run,
list > please, choose run > [run in a joust; cf. 304.15:7, 307.38:8]
5 Or prove yourself, this sad encounter shun,
sad > grievous
6 And seek else, without hazard of your head."
else > {In another manner, place, or time; by other means; under other circumstances} of > to
7 At those proud words that other knight began 8 To wax exceeding wroth, and him aread
wax > grow aread > instructed
9 To turn his steed about, or sure he should be dead.