Ezekiel 38:15
And thou shalt come from thy place out of the north parts, thou, and many people with thee, all of them riding upon horses, a great company, and a mighty army:
Cross-reference
Ezekiel 38:4 is part of the same prophecy, with God leading Gog out at the head of a great army of horses and horsemen.
Ezekiel 38:6 names Gomer and Beth Togarmah from the far north, the same peoples accompanying Gog in verse 15.
Ezekiel 39:2 repeats the image of Gog brought from the north, reinforcing the certainty of the invasion described here.
Zechariah 12:2-4 foretells nations gathered against Jerusalem with horses and riders, paralleling Gog's mounted invasion from the north.
Revelation 20:8 reuses Gog and Magog for the final end-times battle, directly echoing Ezekiel's army from the north.
Zechariah 14:2 speaks of all nations gathered to battle Jerusalem, matching the gathering of Gog's coalition in Ezekiel.
Zechariah 14:3 says the Lord will fight those gathered nations, which is the same outcome as Gog's invasion later in Ezekiel.
Genesis 10:2 lists Magog as a son of Japheth, providing the genealogical origin for the nation from which Gog comes.
Daniel 11:40 also describes a northern king invading with horsemen and chariots at the end time, mirroring Gog's invasion from the north.