What is the ruling on deputizing someone for Hajj or 'Umrah?

Appointing someone to perform Hajj or Umrah on one's behalf has two scenarios:

The first scenario (for the obligatory Hajj/Umrah): Proxy is not permissible unless the person is unable to reach the House [Kaaba] due to a chronic illness from which recovery is not expected, or due to old age. However, if the illness is expected to pass, one must wait. If the person is able, it is not permissible for him to appoint a proxy, because Hajj is a personal physical act of worship, and acts of worship are legislated to achieve devotion and humility before God, which is not realized through proxy.

The second scenario (for voluntary Hajj/Umrah): There is a difference of opinion among scholars regarding this. The stronger opinion is that it is impermissible, and that no one may appoint another to perform a voluntary Hajj or Umrah on their behalf, because the fundamental principle in acts of worship is that a person performs them himself, and these are physical acts of worship that are not valid from another except in cases explicitly mentioned in the Sunnah, and this was not mentioned concerning voluntary Hajj.

However, scholars of the Permanent Committee and Sheikh Ibn Baz hold the view that it is permissible to perform Umrah and Hajj on behalf of a living person who is unable due to old age or an incurable illness, whether it is obligatory or voluntary, basing their argument on prophetic hadiths that permit Hajj on behalf of the incapacitated.