Availability of funds clause in reps & warranties

I am currently reading the Rosenbaum, and have read that reps & warranties might include a "availability of funds clause (usually requested from financial sponsor)".

I have searched for an explanation online but due to the terms being very general, I can't really understand what it is about.

Is it something related to the fact that GPs would need to call the funds from their LPs?

Thanks a lot for any clarifications