Johan

What you have said here makes a lot of sense. But, what comes to mind as I contemplate what you said is; is there anything in the context of the chapter that would confirm that bought has to do with the Hebrews being bought out of slavery from Egypt?
I have read a few commentaries on this passage and I haven't seen that particular understanding. This isn't discounting your understanding, but it does make me wonder.

I am a little too busy to do too much study on that aspect, but it is certainly worth looking into.

Tom