[The Ruling on Performing Hajj from Makkah or al-Madīnah on Behalf of a Man from Yemen]

Answer—and Allah grants success and aid: When Hajj becomes obligatory upon a legally responsible person, its preliminaries also become obligatory upon him. Thus, if the man is in Yemen, it is obligatory upon him to leave his home and traverse the long stages of travel until he reaches the mawāqīt; when he reaches them, he begins the rites of Hajj.
If Hajj became obligatory upon him but he failed to perform it until he was unable to perform it himself, then he must appoint a proxy to carry out what had been obligatory upon him—he hires someone to leave his home on his behalf, traverse the stages of travel until reaching the miqāt, enter iḥrām, and so on.
This is how one fulfills what has become obligatory upon him of the Hajj obligation.
As for hiring someone to perform Hajj on his behalf from among the people of the miqāt or the people of Makkah, then he has not fulfilled everything that was obligatory upon him; he has only fulfilled part of what was obligatory.
If it is said: According to what you have mentioned, two things were obligatory upon him—first: Hajj, and second: its preliminaries. On that basis, the Hajj would be valid while its preliminaries remain in his liability?
We say: What is correct is that which accords with the command of the Lawgiver. We have explained that the one upon whom Hajj is obligatory is, by the Sharīʿah, commanded to leave his home and traverse the stages of travel until he reaches the miqāt, and so on.
Hajj from Makkah has a particular description; Hajj from al-Madīnah has a different description; Hajj from Yemen has yet another description distinct from the first two; and Hajj from China has a description different from those.
Nevertheless, we say: The Hajj is valid in any case—but it does not discharge the Hajj of Islam. With acceptance, the hired proxy is written his wage and reward; however, as we have said, it does not discharge the Hajj of Islam.
- If the Hajj is supererogatory, then the one commissioning it may hire whomever he wishes, from wherever he wishes.
- Hajj may become obligatory upon a person; he then makes a bequest, or he leaves insufficient funds to perform the obligation that had become due upon him. After his death, his guardians or executor wish to perform Hajj on his behalf, but what the deceased left does not suffice—because the costs of Hajj have multiplied greatly—and his children are unable to cover the costs due to poverty, yet they wish to hasten to perform the Hajj. In such a case, there is no harm upon them to hire someone to perform Hajj on behalf of their deceased from wherever is feasible; nothing more is required of them: “Allah does not charge a soul except [with that within] its capacity.” [al-Baqarah:286]
If, however, the estate of the deceased is large, then it is obligatory upon his guardians to fulfill the Hajj from the estate.
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1