It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that a woman from the tribe of Khath'am asked the Prophet (peace and blessings be upon him) for a ruling during the Farewell Hajj and said: "O Messenger of Allah! The obligation of Allah upon His servants regarding Hajj has reached my father while he is a very old man; he cannot sit upright on a mount. Would my performing Hajj on his behalf suffice?" He (peace and blessings be upon him) said to her: "Yes."
Hadith Referenceالمعجم الكبير للطبراني / باب الفاء / 15820