Having heard the great deed performed by his son Bhishma, Shantanu gave that illustrious man the boon of dying at will.
तच्छ्रुत्वा दुष्करं कर्म कृतं भीष्मेण शान्तनुः। स्वच्छन्दमरणं तुष्टो ददौ तस्मै महात्मने॥