Hajj is Fard Once (FATWA)
What do the scholars of the religion say regarding the issue that Zayd is an owner of niṣāb and Ḥajj is farḍ upon him. So, he performed Ḥajj and then returned. Then he made the intention to go for Ḥajj once again, but now he wishes to take his elder son and his wife along. Zayd’s three sons and daughters all lived under him and then he married his daughters off and sent them to their in-laws.
The question is that after Zayd passed away, will the farḍ Ḥajj of the elder son have been fulfilled or not? After Zayd’s death his wealth was distributed and all three of them attained so much wealth that made Ḥajj farḍ upon them, and both brothers had [in the past] given consent to send him along with their father [Zayd], so when this [elder] son goes for Ḥajj how should he make the intention of ‘iḥrām? Now in such a case, will Ḥajj even be farḍ upon him, or will the first Ḥajj be sufficient?
When Zayd takes his elder son along with him for Ḥajj, if his son is bāligh, that Ḥajj will fulfill the farḍ Ḥajj and he should intend the farḍ Ḥajj when making the intention. After the passing away of Zayd, if the three sons attain so much wealth in each of their shares that it becomes farḍ upon them to perform Ḥajj, then Ḥajj will not be obligatory upon the first son who has already performed the farḍ Ḥajj, because the farḍ Ḥajj has been fulfilled. The Ḥajj that he will perform now will be a nafl Ḥajj. As for the other two sons who have not performed Ḥajj, it will be mandatory upon them to perform the [farḍ] Ḥajj.
He [Allāh E] knows best.
Ṣadr al-Sharī`ah, Muftī Amjad `Ali al-A`ẓamī