There appears to be a confusing / contradictory sequence of events occurring when Joseph's brothers first appear before him in Egypt.
Refer to Breishit 42:16 - 19
In v. 16, Joseph tells to his brothers to send one person back to bring down their other brother, and the rest of them will be imprisoned in Egypt.
Apparently, that didn't happen, or Joseph didn't wait to see if it would happen, since, in verse 17, he imprisons all his brothers for 3 days.
Finally, in verse 19, Joseph says, one of your brothers will be imprisoned, here, and the rest of you can go back to bring your other brother. It seems like the opposite of the original arrangement.
Why did Joseph change the entire arrangement between verses 16 and 19?