Sahih Bukhari
Pilgrimmage (Hajj)
Volume: 002 / Book Number: 026 / Hadith Number: 663
Narrated 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.