Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates that a man came to the Messenger of Allah (peace and blessings be upon him) and said: "O Messenger of Allah, my father is very old and is unable to perform Hajj; shall I perform Hajj on his behalf?" He (peace and blessings be upon him) said: "If he had a debt, would you pay it?" He said: "Yes." He (peace and blessings be upon him) said: "Then the debt owed to Allah is more deserving to be paid; perform Hajj on his behalf."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11361