Supporting document returned

Hi
I have applied for citizenship at the end of March. And they asked for my previous all passports end of May.

This week I have received both my passports back with a letter saying “please find your supporting documents, we do not need to see them again”
And signed by the case worker.

What does it mean?
There is nothing else in the parcel confirming approval/rejection or ceremony confirmation.
I am really confused.

Please let me know if anyone has any clue about this .

What does it mean?

It means they simply sent your documents back and likely copied what they needed.

There is nothing else in the parcel confirming approval/rejection or ceremony confirmation.

Probably because they are still busy with your application.