That is a strange way to say thank you to the host. 🤨

Ignore the demand. At dinner ask them what tasks about the house and property they will doing. Give a list of what needs to be done. Tell them it’s a condition of staying. It’s best to talk about expectations rather than have them unsaid.

Of course they may be agreeable and will then forget to do anything. There may also be drama. Then I suggest forget to invite them in the future.