Charles Ellicott Commentary Numbers 16:30

"But if Jehovah make a new thing, and the ground open its mouth, and swallow them up, with all that appertain unto them, and they go down alive into Sheol; then ye shall understand that these men have despised Jehovah." — Numbers 16:30 (ASV)

Make a new thing.— Literally, create a creation — that is, do something until now unknown.

Into the pit.— Literally, into Sheol.