What does 1 Samuel 10:19 mean?

'But today you've rejected your God, the one who saves you from all your problems and dangers. You said, 'No, we want a king instead.' So now, line up by your tribes and families.' 1 Samuel 10:19 - Modern Text Bible

(Samuel points out that asking for a king is actually turning away from trusting God, but he tells them to get ready for the selection.)