I think you got the text from reformed.org / apuritansmind.com.
In their answer for WSC Q20, they accidentally put the comma inside the prooftext reference ([a,]). Your text should have a comma after “elected some to everlasting life”, but it doesn’t because the source was poorly formatted.
Yes. Sorry for not replying. Content fixes take a lot more time since my current method for these fixes is to tweak the import script and then the fix actually gets applied when I next reimport the database (and I need to find a better solution for this, since I only really want to reimport the database one more time)