Sulayman bin Yasar narrates from Sayyiduna Abdullah bin 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) on the morning of Muzdalifah, while Sayyiduna al-Fadl (may Allah be pleased with him) was riding behind him (peace and blessings be upon him). She said: The obligation of Hajj has reached my old father, and he cannot even stay seated on a mount; what is your (peace and blessings be upon him) view, may I perform Hajj on his behalf? He (peace and blessings be upon him) said: "Yes."
(b) Amr bin Dinar, narrating from Imam al-Zuhri before seeing Ibn Shihab, adds something to it: the woman said: Will it benefit him? He (peace and blessings be upon him) said: "Yes, it is just as if someone owed a debt and you paid it off."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9852