“shake hands.” The Hebrew is more literally something like, “striking hands,” but it refers to a custom that was either the same as our handshake or similar to it. The custom occurs here as well as in Proverbs 6:1 and 17:18.
Although it is not specifically stated in this verse, the scope and context of Scripture makes it clear that this verse is speaking about not making unwise agreements. It is not saying not to make agreements at all, although there is a sense in which putting up security for someone else’s loan is always risky, no matter who the person is. Many people in the Bible make agreements, in fact, a covenant is an agreement. Also, other verses in Proverbs that speak of shaking hands make it clear that the agreement is an unwise one (cp. Prov. 6:1-5 and 17:18). [For more on the custom of shaking hands, see commentary on Prov. 6:1].