Ezekiel 38:7,8

“Be prepared, yes, prepare yourselves, you and all your companies who are gathered to you, and you be a sentinel for them. After many days you will be mustered.”

Gog is told to put his armies on the alert and act as their sentinel so that they will know when to act. He is to wait for the call of God. It is a comfort to the people of God to know that even Gog is ‘chained'. But the day will come, after many days, when they will be mustered, led along by Yahweh by the hooks in their jaws (Ezekiel 38:4). Everything about this passage delays it into the future, in contrast with the previous oracles on the nations. It must await God's timing. This is the mystery of history. They work out their own will, and yet they do God's will as well.