Genesis 42:16-19

16Send one of you [back home], and let him bring your brother [here], while [the rest of] you remain confined, so that your words may be tested, [to see] whether there is any truth in you [and your story]; or else, by the life of Pharaoh, certainly you are spies.”

17Then Joseph put them all in prison for three days.

18Now Joseph said to them on the third day, “Do this and [you may] live, for I fear God:

19if you are honest men, let one of your brothers be confined in your [place here in] prison; but as for the rest of you, go, carry grain for the famine in your households,