Odysseus shows that he is patient in chapter 18. He wants so badly to kill Iros out of frustration and annoyance, but he must not give anything away just yet. He must wait for his opportunity to get revenge on the suitors, and killing Iros out of frustration would only draw attention to himself.
"Then Odysseus considered whether he should let drive so hard at him as to make an end of him then and there, or whether he should give him a lighter blow that should only knock him down; in the end he deemed it best to give the lighter blow for fear the Achaeans should begin to suspect who he was."
So his patience is tried here, and he shows that he can wait for what really matters most.