And once again, we've left context out where this was socially acceptable slavery for debts which you insist changes context, even though it is in the same paragraph.
Alright - I went ahead and dug into it since you were so insistent that the subject does not change within that set of verses.
I am using your preferred translation as far as I understand it (NASB), and traced it back to the original hebrew.
Let's take it line by line.
LEV 25:39 "If a countryman of yours becomes so poor with regard to you that he sells himself to you, you shall not subject him to a slave’s service."
This verse is clearly telling us that if a fellow countryman of ours sells himself to us to get out of debt we should NOT treat them as a slave, thus drawing a distinction between slaves and those indebted to us.
The word 'slave' is 'ebad' in the original Hebrew, which is defined as "slave/servant."
The subject here is our fellow countrymen, and we are being told told NOT to treat these fellow countrymen as 'ebed.'
LEV 25:40 "He shall be with you as a hired man, as if he were a sojourner; he shall serve with you until the year of jubilee."
Instead, we are told to treat the indebted servant as a 'hired man,' which came from the original Hebrew 'Sakiyr,' defined as "hired/laborer."
So there is a distinction being made between treating someone as a slave (ebed) or as a hired laborer (Sakiyr).
LEV 25:41 "He shall then go out from you, he and his sons with him, and shall go back to his family, that he may return to the property of his forefathers. "
Once this indebted person's debts are worked off, they may return to their lives.
We are still talking about our fellow countrymen.
LEV 25:42 "For they are My servants whom I brought out from the land of Egypt; they are not to be sold in a slave sale."
This is where it gets interesting - because we now have a distinction between OUR slaves/servants and GOD'S slaves/servants.
This verse clearly states that these indebted fellow countrymen are God's slaves, using the same Hebrew word 'ebed' in the original text.
So because of this we are not to sell them in a slave sale (again, using the word 'ebed').
Remember, this is all still referring to the original subjects from verse 39, our fellow countrymen.
They cannot be our 'ebed,' because they are God's 'ebed.'
We are to treat them as 'Sakiyr,' not 'ebed.'
LEV 25:43 "You shall not rule over him with severity, but are to revere your God."
Again, in reference to the indebted fellow countrymen of verse 39 who we were told not to treat as slaves ('ebed').
LEV 25:44 As for your male and female slaves whom you may have—you may acquire male and female slaves from the pagan nations that are around you.
And this is where the shift in subject happens. Now this verse is saying that in regards to the male and female 'ebed' (servants/slaves), you may get them from the surrounding nations.
Notice that in verse 39 we are told not to treat the indebted as 'ebed,' and now we are told we may acquire 'ebed' from the surrounding nations.
The same Hebrew word is used in verse 39 and 44, the distinction being drawn in verse 40 which uses a different word (Sakiyr) to tell us how to treat the indebted.
Clearly this is referring to two different classes of people. We have now shifted to a new subject, our 'ebed' as opposed to our fellow countrymen.
The following two verses go on to clarify the distinction that it is only these foreigners that we may take as slaves, adding that even their children will become our property and we may pass them all along to our children.
BUT...(referring back to verse 39) our own countrymen will not be our slaves.
LEV 25:45-46 "Then, too, it is out of the sons of the sojourners who live as aliens among you that you may gain acquisition,
and out of their families who are with you, whom they will have produced in your land; they also may become your possession.
You may even bequeath them to your sons after you, to receive as a possession; you can use them as permanent slaves.
But in respect to your countrymen, the sons of Israel, you shall not rule with severity over one another."
A distinction is clearly being drawn between two groups of people from verse 39 to 46.
The distinction is made clear at verse 39 & 40, while the shift of subject happens at verse 44.
One group is not to be enslaved, the other is permissible to enslave.
I'm not certain how you could possibly read it any other way.