Sahih Bukhari Volume 2, Book 26, Hadith Number 663.

Narated By Abu Said Al-Khudri : The Prophet said “The people will continue performing the Hajj and ‘Umra to the Ka’ba even after the appearance of Gog and Magog.”

Narrated Shu’ba extra: The Hour (Day of Judgment) will not be established till the Hajj (to the Ka’ba) is abandoned.