Surety . . . this is a topic that Proverbs spends a decent amount of time discussing. We are told very clearly that we are not to become surety for anyone. But maybe we're getting ahead of ourselves. What does it mean to be "surety?"
Surety is giving a pledge or a guarantee. It means we take responsibility for debt of someone else. The Bible makes is clear to us that this is not a wise thing to do. In fact, what is said here is that if we have become surety for a neighbor, or have given a pledge to pay a debt for them - that we've put ourselves in very serious danger. It is referred to as being caught in a snare.
The snare mentioned here is one that was used to capture birds. The word figuratively means to catch a person or persons in an undesirable situation. The bait for this trap is usually a desire for something that is outside of God's will. It can be pride, a desire to please others more than pleasing God, or any number of other things, but whatever it is, it lures us into a trap.
Why is this a trap though? Surety is a trap because we are putting ourselves into a position where we are guaranteeing the actions and character of someone else. If they do not pay - we are on the hook for whatever they don't do. Thus, with a promise or a simple signing of our name on a dotted line, we've placed ourselves in bondage for someone else's debt and responsibility. That is not wise - because we have our reputation on the line until that debt is paid. No wonder God says for us to stay clear of situations where we place ourselves as surety for someone else. It puts us into an unnecessary jeopardy regarding our reputation - and because we are seen as representatives of God - His as well.