Although Uzziah recognizes truth in what Judith says, he is not prepared to break his oath (referred to by Judith at verse 11, but not called an oath by the narrator at 7.30-31) in compliance to the wisdom of her proposal. So far, of course, all she has proposed is that the city not surrender.

Very thirsty means “dying of thirst” (Good News Translation, Contemporary English Version) or “so thirsty that they were about to die.”

They compelled us to do for them what we have promised: See the discussion at verse 11.

And made us take an oath which we cannot break: This clause has practically the same meaning as the previous one. So Contemporary English Version combines them into “and they begged us until we finally made a solemn promise that we can’t break.”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Judith. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here.