It’s listed as a receivable since the sale was booked. It is an asset since the cash hasn’t traded hands yet but is expected to soon convert. Receivables are booked after the sale, not before.
Some companies record revenue upon shipment or receipt and if it was a pending sale it wouldn’t be listed as a receivable, but rather unearned revenue as a liability since their end of the agreement hasn’t been fulfilled for it to be listed as rev. Not the case here.