Can an elderly person who cannot travel appoint someone to perform حج on their behalf?

If an elderly person is permanently unable to perform حج due to old age, chronic illness, or physical incapacity, they may appoint someone to perform حج on their behalf. This is based on the hadith: 'A woman from Khath'am said: O Messenger of Allah, my father is an elderly man who cannot sit firmly on the mount. Can I perform حج on his behalf? He said: Yes' (Sahih al-Bukhari 1513, Sahih Muslim 1334). The proxy must have already performed their own واجب حج first. Sheikh Ibn Baz stated: 'Proxy حج is valid for the permanently incapable' (Fatawa Ibn Baz, vol. 16).