BABHIKHAN (VIBHISHANA) (The Gurmukh) Rama killed the egoist Ravana, the knowledge given by the Guru was like the secrets told by Vibhishana. (Ramkali M. l, Siddh Goshta, p. 942) The Lord bestowed kingship on Babhikhan (Vibhishana) for a long time. (Maru Namdev, p.105) Vibhishana was the younger brother of the demon-king Ravana of Lanka. He was a righteous person and was against any act of unrighteousness. It was he who opposed the unrighteous act of Ravana in carrying off Sita by force.

When Hanuman was taken in the presence of Ravana and claimed to be the ambassador of Rama; and also asked him to undo the wrong done by him in order to save himself from the vengeance of Rama; Ravana, in great fury ordered him to be put to death. At that time Vibhishana reminded his brother that as ambassador, the life of Hanuman was sacred. On another occasion, when Vibhishana advised Ravana about the restoration of Sita, the demon-king, in great ire, kicked him. In great disgust he left Lanka and sided with Rama. When the war ended with the slaying of Ravana, Rama installed Vibhishana as the king of Lanka.

References :

1. Kohli, Surindar Singh, Dictionary of Mythological References in Guru Granth Sahib, 1993