But again, in its time thou didst bring the flood upon the inhabitants of the world and destroy them: See Gen 6.1–7.24. But again is better rendered “But then.” In its time may be translated “eventually” or “at the proper [or, right] time.” New English Bible has “in due time.” The idea of this verse is that God brought on the flood when he had had enough of human sinfulness. Here is an alternative model for it:

• But then, when you thought the time was right, you sent a flood that destroyed the world’s population [or, the people of the world].

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.