In several Aayaat it is mentioned that Haj is fardh. The following Aayat, however, is the clearest and most explicit.
“It is fardh upon mankind; for one who has the means to reach there, to make Haj of the Baitullah for (the Ibaadat of) Allah. Whoever rejects then verily Allah Ta’ala is not in need of the world.” (Surah Aali Imraan, 97)
In this Holy Aayat, together with mentioning that Haj is fardh, sincerity in intention and the condition for it being fardh – the means – are also stated. In addition, a warning has been given that whoever rejects Haj as being fardh is a kaafir, or whoever does not go for Haj in spite of being able to and he dies, he resembles a kaafir.
Hazrat Ali (Karramallahu wajhahu) thus reports from Rasoolullah (Sallallahu alaihi wa sallam): “Whoever owns a means of transport and provision to take him to the Baitullah and still does not make the Haj, then let him die a Yahoodi or a Nasraani, it matters not.”