The Book Pertaining to the Turmoil and Portents of the Last Hour (Kitab Al-Fitan wa Ashrat As-Sa`ah)
Muslim :: Book 41 : Hadith 7016
This hadith has been narrated on the authority of Jabir with the same chain of transmitters but with this addition that Gog and Magog would walk until they would reach the mountain of al-Khamar and it is a mountain of Bait-ul-Maqdis and they would say: We have killed those who are upon the earth. Let us now kill those who are In the sky and they would throw their arrows towards the sky and the arrows would return to them besmeared with blood. And in the narration of Ibn Hujr (the words are):" I have sent such persons (Gog and Magog) that none would dare fight against them.