Charles Ellicott Commentary Proverbs 28:18

"Whoso walketh uprightly shall be delivered; But he that is perverse in [his] ways shall fall at once." — Proverbs 28:18 (ASV)

He that is perverse in his ways.— Literally, two ways. (Compare note on Proverbs 28:6.)

At once — i.e., all of a sudden, without warning.