Part of the four stately in their walk, Proverbs 30:29–31.
Quick answer
The first of four, and the obvious one. What the verse praises is not the lion's power but its composure: it does not step aside for anything.
Read the whole unit
Four creatures admired for how they carry themselves, with no instruction attached.
Read the whole unit
The last of the numerical sayings, and the least moral. Four things that walk well. There is no lesson attached, no warning, and nothing anybody is told to do. Agur simply admires the way certain creatures move, and the saying is content to stop there.
The list is a lion, then something the translators cannot identify, then a male goat, then a king with his army around him. Its subject is bearing rather than power: not what these four can do, but how they carry themselves while doing it. The lion is described as not turning aside from anything, which is a statement about composure rather than about strength.
And then the chapter's next sentence is "If you have been foolish in exalting yourself." Nothing joins them grammatically, and the catalog does not claim the editor intended it. But the placement is there, and it reads the way the book usually reads: an admiring look at four things that carry themselves well, immediately followed by an instruction for the person who has been trying to. Stateliness, in this arrangement, is something you have or do not. It is not something you can perform your way into.
What this verse contributes
The standard the other three are measured against, and the specific thing being admired. The second line does not describe a lion attacking. It describes a lion not moving out of the way, which is a statement about how it walks rather than what it can do.
That distinction runs through the whole list. A creature that never has to yield walks differently from one that does, and the saying is watching for that difference. It is the only item in the four whose right to it nobody would question.
Related: Proverbs 28:1 · Proverbs 19:12
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.