I will be surety for him: to be surety for someone means in a legal sense to be responsible for another’s debts, to serve as guarantor. However, the term is used here, as in Psa 119.122, with the general meaning of promising to help and protect. A common rendering is “I promise to take care of him.”

Of my hand you shall require him: this expression was first used in 31.39 in a conversation between Jacob and Laban. See there for translation.

If I do not bring him back to you and set him before you: set him before you is literally “set him before your face,” an expression that means “return him safely to you.” See Good News Translation.

Then let me bear the blame for ever is the consequence of the “if” clause. The literal expression is “I shall be a sinner against you all the days.” The verb rendered bear the blame means to “be guilty,” “be at fault.” We may translate, for example, “I shall be forever guilty” or “you can blame me all the rest of my life.”

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .