The Hegh'bat was a traditional Klingon ritual suicide. According to law and ritual, when a Klingon could not stand and face their enemies as a warrior and they had become a burden to their family and friends, it was the time for Hegh'bat. The honor of helping the warrior would fall to a family member, preferably the oldest son. That person's role was to hand the incapacitated Klingon a knife so that they could plunge it into their heart. The family member would then remove it and wipe the blood on their sleeve.
In 2368, facing a life of paralysis, Worf asked William T. Riker to perform the ritual. Riker declined, not wishing to see Worf die. In an attempt to convince him not to give up, Riker later reminded Worf about whose duty it was primarily, surmising (correctly) that Worf would not be able to bring himself to ask Alexander to kill him. (TNG: "Ethics")