It is probably a little shocking to us in the West how often the Word of God talks about the issue of surety. We are not used to such strong words regarding debt and regarding guaranteeing the debt of others. But then again this shouldn't be too shocking because as a nation we are a debt loving people. We have over 14 trillion dollars in government debt and are one of the worst debtor nations in the world. The people of the United States are not much better having become one of the richest nations in the world - but deceptively - on the basis of debt rather than real wealth.
It might be wise for us to learn from the Scriptures on this matter because God warns in Isaiah about those who become rich with loans. This kind of wealth is not wealth at all. First of all you don't own anything when you "own" it with debt - the bank owns it. If you want to test this theory try missing payments on your "so-called" wealth - and find out how quickly the bank will eventually come and prove who owns what. Second, when you become wealthy with debt - you are paying much more for what you are buying than what it is worth. I remember when my family went to sign for our house loan. I was horrified when I saw that I was paying close to triple what the house actually cost to buy it with a loan. That was an eye-opening experience for me.
The problem with going surety for someone else is that you are in effect giving a guarantee that you will pay their debt if they do not. To counter this our society has something called collateral, which is something of value that is put up to secure the debt. When you have collateral you don't have surety - because if the person defaults on their debt, you can take the collateral to pay for what they do not pay. Good collateral is when you have something close to equal in value to what is borrowed. Here in this proverb though, we have a situation where someone does not have sufficient collateral for their loan - and therefore all they have is their garment. God's Word forbids taking a man's "cloak" overnight because for the poor this was all they wrapped themselves in to protect from the cold. Yet what we see here is that we are told that when a man becomes surety for a stranger - to even take his garment - and when he does this for a foreigner - to hold him in pledge for what he has foolishly guaranteed. The teaching here is that there has to be a price for foolishness - and especially foolishness with money. But there is a more sinister possibility here that we need to examine.
Several commentators see this word "stranger" as a sign that this loan was also given because of an involvement with an alluring woman. If you remember elsewhere in the book of Proverbs, the prostitute is often called a "strange woman." There is a warning then here given especially to men who deal with money. That warning is not to be pulled into giving money because we are taken by a woman's alluring appeal. We all know of the scenes where a woman uses her sexual appeal to get what she wants. This statement is possibly given to warn men to steel their hearts when an attractive woman comes for an appeal. We are to loan money on the basis of wisdom - not in response to our glands and egos.
God gives to each of us a provision - and that provision is meant to be used according to the wisdom that He has given in His Word. We MUST be careful to follow biblical financial principles. When we vary from them we will face loss and face difficult times because we did not listen to His wisdom or follow it. We need to realize how often the book of Proverbs offers to us God's take on financial matters - and follow His wisdom to the place of His blessing and protection. If we do not, we may lose our shirt - or at least our garment.