Covered wagons - Some prefer to render “litter Isaiah 66:20 wagons:” i. e. litters which were not on wheels, but borne by two oxen, one in front and one behind. Such conveyances would probably be more convenient than wheeled wagons in the rough country to be traversed.
Related Commentaries of Numbers 7:3
Numbers 7:3
3 And they brought their offering before the LORD, six covered wagons, and twelve oxen; a wagon for two of the princes, and for each one an ox: and they brought them before the tabernacle.