If integrated into the book of Daniel: 13.47.

All the people turned to him, and said: Before Daniel shouted his protest, he had just been one other person in the crowd. Now everyone’s attention is fixed on him. Good News Translation‘s model shows this very well: “Everyone turned around to look at him and asked.”

What is this that you have said?: The task here is to find an appropriate idiomatic response to Daniel’s protest. The people, on their way to the execution, are suddenly surprised, shocked, and perhaps there is a momentary question in their minds as to whether he might be right. At any rate, it is not that they did not hear him clearly and are asking him to repeat it. In effect they are asking what basis he has for protesting their action. Good News Translation “What are you talking about?” is good, suggesting the people are denouncing Daniel. New English Bible is also good with “What do you mean by that?” which suggests they are challenging Daniel.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on The Shorter Books of the Deuterocanon. (UBS Helps for Translators). New York: UBS, 2006. For this and other handbooks for translators see here.