Against them — That they might be witnesses of the event, and, upon their success, which they doubted not of, might fall upon Moses and Aaron. And it seems by this that the people were generally incensed against Moses, and inclined to Korah's side. The glory appeared — In the cloud, which then shone with greater brightness and majesty, as a token of God's approach and presence.
Related Commentaries of Numbers 16:19
Numbers 16:19
19 And Korah gathered all the congregation against them unto the door of the tabernacle of the congregation: and the glory of the LORD appeared unto all the congregation.