It is best to consider verses 5 and 6 together, since their subject matter is so closely linked, as well as their structures.

For your iniquity teaches your mouth: verse 5 begins with a Hebrew conjunction which here has the function of English “Since” or “Because,” making both lines of verse 5 subordinate to verse 6. This first line is ambiguous because it is not certain from the Hebrew whether your mouth or your iniquity is the subject of teaches. Most translators take iniquity to be the subject, and so Eliphaz asserts that Job’s wickedness teaches his mouth what to say. Some understand that it is the mouth (what Job says) that “reveals” his iniquity, and this seems to be the understanding of Good News Translation, “Your wickedness is evident by what you say.” These two meanings do not differ in substance. In many languages it is not possible to say that an abstract term such as wickedness teaches a body part such as the mouth. Therefore the construction must be changed to say, for example, “Because you are wicked, you talk the way you do” or “You are wicked, and that is what makes you say the things you say.”

And you choose the tongue of the crafty: Eliphaz asserts that Job follows a form of speech used by people who deceive others. Tongue of the crafty is the “speech, language, manner of arguing” used by persons who are “cunning, clever, deceptive.” This line may also be expressed, for example, “you talk like a deceiver,” “you use deceptive words,” or “you deceive people by using clever words.” In many languages figurative expressions are commonly used to express this thought; for example, “you talk with a forked tongue” or “there are two hearts behind your words.”

Your own mouth condemns you, and not I: verse 6 is the result of the two reasons given in verse 5; that is, “Because you are wicked and crafty, it is your mouth that condemns you.” In 9.20 Job said “Though I am innocent, my own mouth would condemn me….” Those words give Eliphaz the opening to agree with Job, but in a much wider context than Job meant in chapter 9. Good News Translation has restructured line a by shifting and not I to the front, and combining Your own mouth in line a and your own lips in line b. This line may also be rendered, for example, “I do not condemn you; your own mouth condemns you,” “You do not need me to say you are guilty; your own mouth does that,” or “I do not say ‘Job, you are guilty.’ Your own words say it.”

Your own lips testify against you: the poet has moved from mouth to tongue to lips as images of Job’s speech, none of which appear in Good News Translation. Lips testify against you is a law court expression used similarly in Jeremiah 14.7; 2 Samuel 1.16. The meaning is “your words witness against you,” “what you say accuses you,” or “your talk shows that you are guilty.”

Quoted with permission from Reyburn, Wiliam. A Handbook on Job. (UBS Helps for Translators). New York: UBS, 1992. For this and other handbooks for translators see here .