'Tribes' in the Bible

Jesus said to them, "Most certainly I tell you that you who have followed me, in the regeneration when the Son of Man will sit on the throne of his glory, you also will sit on twelve thrones, judging the twelve tribes of Israel.

and then the sign of the Son of Man will appear in the sky. Then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of the sky with power and great glory.