From Sahih Muslim (Hadith 3251):
Abdullah b. 'Abbas reported that while al-Fadl b. Abbas had been riding behind Allah's Messenger (ﷺ) a women of the tribe of Khath'am came to him (to the Holy Proppet) asking for a religious verdict. Fadl looked at her and she looked at him. Allah's Messenger (ﷺ) turned the face of al-Fadl to the other side. She said:Messenger of Allah, there is an obligation from Allah upon His servants in regard to Hajj. (But) my father is an aged man; he is incapable of riding safely. May I perform Hajj on his behalf? He said: Yes. It was during the Farewell Pilgrimage
Reference: Muslim 3251