Star Trek: Deep Space Nine1993

Lt. Commander Worf:
You know that I was forced to fight the Jem'Hadar guards in the camp. Each day they would call me to the ring, and each day I would fight. But then there came a day when I... wavered.

Captain Sisko:
You mean you didn't want to go back into the ring?

Lt. Commander Worf:
No, I mean I considered letting them kill me. It seemed like the only way out. Just before I went into the ring, Martok turned to wish me success. And then he saw what I was planning, he saw it in my eyes. It was a moment of tova'dok.

Captain Sisko:
Of what?

Lt. Commander Worf:
There is no Human word for it. It is a moment of... clarity, between two warriors on a field of battle. Much is said without the need for words. In that moment, he knew what was in my mind. Once I realized that he saw my intention to give up I could no longer go through with it. I went back into the ring and fought once more. He had given me his warrior's heart. - Perhaps it is something a Human cannot understand.