​Buying a Business – why buy the Accounts Receivable?

Just trying to wrap my head around this, why if I pay a 2-3x multiple on Adjusted EBITDA would I then ALSO pay for the Accounts Receivable-Accounts Payable on top of that if that AR and AP was used to generate the EBITDA I’m already paying for. Is it not double dipping?

Inventory I understand more because the product has yet to be sold and moved to the Income Statement, however, the Sales on AR are already on the Profit & loss and factored into the EBITDA. Any idea why you would pay for AR on top of a multiple?

Added Context: I understand AR is cash to be collected but if we’re looking at Accrual Net Income this is already factored in as part of Sales which flows into the EBITDA multiple