What is a quote that illustrates that Fortinbras is marching his army in order to regain his honor?

Throughout the play, it is understood that the young Fortinbras is marching on Denmark with the ultimate goal of regaining his honor through recapturing lands his father lost to the late King Hamlet.
In act 1, scene 1, Horatio explains to the guard Marcellus why there is a sudden military and naval buildup in Denmark. He states that, now that King Hamlet is dead, Fortinbras—to prove his mettle or courage (i.e., gain his honor)—plans to fight to get these lands back:

Now, sir, young Fortinbras,
Of unimprovèd mettle hot and full,
Hath in the skirts of Norway here and there
Sharked up a list of lawless resolutes,
. . . to recover of us, by strong hand
And terms compulsatory, those foresaid lands
So by his father lost.

In act 4, scene 4, Hamlet compares his own perceived lack of courage and honor (in not yet killing Claudius to avenge his father's death) with Fortinbras's act of bringing an entire army to Denmark for the sake of honor.
Hamlet's language here is interesting. He is trying to motivate himself to kill Claudius by using Fortinbras as an example of a son honorably avenging his father, but this speech also suggests that Hamlet thinks Fortinbras is going completely overboard. Is it really honorable, he seems to ask, to risk so many innocent lives "for an eggshell" or "to find a quarrel in a straw?" However, there is no doubt that Hamlet understands that Fortinbras is perceived by others as honorable:

Witness this army of such mass and charge
Led by a delicate and tender prince,
Whose spirit with divine ambition puffed
Makes mouths at the invisible event,
Exposing what is mortal and unsure
To all that fortune, death, and danger dare,
Even for an eggshell. Rightly to be great
Is not to stir without great argument,
But greatly to find quarrel in a straw
When honor’s at the stake.

In act 5, scene 2, Fortinbras himself, coming across the dead bodies in the royal court, states that he has honorable "rights" and "claim[s]" on Denmark:

I have some rights of memory in this kingdom Which now, to claim my vantage doth invite me.

Any of these quotes might work for you, depending on what your larger assignment is.