It was narrated from Al-Fadl bin 'Abbas, that:
He was riding behind the Messenger of Allah [SAW], when a man came and said: O Messenger of Allah, my mother is an old woman; if I put her on a mount she cannot sit firmly, and if I tie her, I fear that I may kill her. He said: Do you think that if your mother owed a debt you would pay it off for her? He said: Yes. He said: Then perform Hajj on behalf of your mother.