This is a warning to avoid the way of the wicked or perverse person. The two lines are not strictly parallel, but they do have elements that contrast with each other in meaning.
“Thorns and snares are in the way of the perverse”: On the basis of one ancient version, some translations make a slight change in the Hebrew term “Thorns” and get “traps and snares”; Revised English Bible, for instance, has “Snares and pitfalls lie in the path. . .,” and Good News Translation appears to translate both terms by the single word “traps.” Most versions, however, retain the Hebrew “thorns.” This line pictures the life of a person as a path or road, and the “Thorns and snares . . . in the way” represent dangers and troubles that may come to the person. This is a picture that is used in many languages and cultures around the world, so some translators would be able to retain it. Where this is not the case, we may be able to say, for example, “All kinds of dangers and troubles in life are waiting for the wicked person.” For the sense of “the perverse” see 2.15, where it is translated “crooked.” This term is often rendered as “wicked” or “crooked.”
“He who guards himself will keep far from them”: “He who guards himself” is literally “the one keeping his soul.” Some translations render this as “the cautious [person]” (Revised English Bible, New Revised Standard Version). Others have something like “whoever values life” or “if you love your life” (Good News Translation). “Keep far from them” is a figurative way of saying “avoid those dangers.” Many languages will be able to use expressions similar to the English “steer clear of them” (Revised English Bible), “stays far from them” (New International Version), or “keep out of their way.” One rendering of this line says, “If a person wants to keep safe, he must watch where he is going and avoid all these bad things.”
Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Proverbs. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .
