In the Yuddha Kanda of the Valmiki Ramayana, Vibhishana, the brother of Ravana, comes to Rama’s camp to change sides. The monkey king Sugriva wants him killed. “He may be a spy of Ravana the king of demons,” he warns. Hanuman speaks for him: “I do not doubt him.”
Rama decides: “He who seeks refuge in me just once, telling me that ‘I am yours’, I shall give him assurance of safety.”