We belong to God. The Lord is helping His people understand this – the firstborn of the flocks belong to God, the firstborn sons have to be “bought back” (=”redeemed”) – all emphasizing that we ALL belong to God.
God leads them out of Egypt but He stays with them. They belong to Him, and so He leads them – not on the easiest route, but on the best route. He does not lead them straight into danger – they have just come out of slavery. They need to know Him more, know His will and law, and know how to worship Him. They need to learn to trust Him. I need all of these things, too. And it all starts with me understanding that I belong to Him, and He has set me free from slavery.
God never leaves them – His love never fails.