Ali bin 'Ayyash علي بن عياش · The Book of the Etiquette of Judges

A man asked the Messenger of Allah : "The (command to perform) Hajj has come while my father is an old man and cannot sit firmly in the saddle, and if I tie him, I fear that he may die. Can I perform Hajj on his behalf?" He said: "Do you think that if he owed a debt you would pay it off for him?" He said: "Yes." He said: "Then perform Hajj on behalf of your father."