Quick answer
Contempt for instruction has a cost, and respect for it has a return. The verse is about posture toward counsel, not about a legal code.
Read both lines
"The word" and "the commandment" here belong to the same household setting as verse 1's father's instruction. Proverbs is not quoting Sinai; it is talking about the teaching a person has been given and what they do with it, the way 6:20 called a mother's teaching torah. The verb behind "fears" is the same root as the book's motto, and read with 8:13's definition it means something closer to taking seriously than to being frightened. What the verse contrasts is a person who treats counsel as beneath them and a person who treats it as weighty.
Related: Proverbs 6:20–23 · Proverbs 8:13 · Proverbs 13:18
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.