5 Himself in straiter bonds too rash implies,
Himself > (The horse; allegorically, the knight also: cf. e.g. 102.8:4) straiter > stricter, tighter, more confining rash > hastily; suddenly implies > enfolds, entangles
6 That to the ground he is perforce constrained
That > [So that] perforce > by force; perforce
7 To throw his rider: who can quickly rise
can > did
8 From off the earth, with dirty blood distained;
distained > stained; defiled, sullied
9 For that reproachful fall right foully he disdained.
reproachful > shameful (of the ignoble means whereby it was brought about) he disdained > he disdained; moved him to anger; moved him to indignation