Firstly: The command of Allah Most High. He says:
وَلِلَّهِ على الناس حج البيت من استطاع إليه سبيلا
Meaning: Whoever among the people has the means to do so, it is an obligatory duty upon him, for Allah, to perform Hajj to that House.
Secondly: The hadith of the Prophet (peace and blessings of Allah be upon him). He said:
(a) Islam is founded upon five pillars:
(1) To testify that there is no deity worthy of worship except Allah and that Muhammad (peace and blessings of Allah be upon him) is the Messenger of Allah,
(2) To establish Salah,
(3) To give Zakat,
(4) To observe Sawm during the month of Ramadan, and
(5) To perform Hajj to the Sacred House of Allah. (Bukhari)
(b) O people! Allah has made Hajj obligatory upon you, so perform Hajj. (Muslim)
(Surah Aal ‘Imran: 97)