I will surely avenge them: Compare Deut 32.43. The adverb surely may be rendered “Let there be no doubt” (Good News Bible) or “Know for certain” (Contemporary English Version). The pronoun them refers to the innocent people who have been murdered. Translators can make this clear by rendering this clause as “Let there be no doubt. I will take vengeance on behalf of the innocent people who have been murdered.”

For says the Lord, see the comments on verses 5 and 8-9. Again, it is not necessary to repeat this clause unless it will be good style in the translator’s language.

And will receive to myself all the innocent blood from among them: Since blood stood for life (Lev 17.14), God says here that he will accept into heaven all those who have been killed unjustly. The innocent blood refers again to the murdered good people, and so does the pronoun them. This clause may be translated “and I will take those innocent people into my own care.”

An alternative model for this verse is:

• Know for certain that I, the Lord, will take vengeance on behalf of the innocent people who have been murdered, and I will take those innocent people into my own care.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Esdras. (UBS Helps for Translators). Miami: UBS, 2019. For this and other handbooks for translators see here.