Is the home delivery of restaurant food considered an instance of selling deferred for deferred, and why are these restaurants spreading?

It is permissible to sell goods described in obligation (such as home food delivery) if the price is paid in full at the contracting session. This is known as "forward sale" (بيع السلم). However, if the requested item requires preparation and processing based on the customer's order (such as restaurant orders), this is considered "manufacturing contract" (الاستصناع). In this case, it is permissible to pay the price in advance, pay part of it, or defer it, which distinguishes it from a forward sale. As for grocery and store orders, their permissibility falls under two aspects: First, it is permissible for the capital of the forward sale to be delayed by a day or two, provided that the delay is not stipulated in the contract. Second, considering this transaction as a promise to sell, and that the actual contract takes place upon delivery of the goods and receipt of payment.