Is it permissible to purchase something without the formula of offer and acceptance if one is confident that the seller will not retract their sale?

A sale has two forms: verbal (offer and acceptance) and practical (mutual consent, mu'atah). The offer (ijab) is what comes from the seller indicating the sale, and the acceptance (qabul) is what comes from the buyer indicating acceptance of the offer. Mutual consent (mu'atah) is when a sale and purchase occur without verbal utterance; for example, the seller displays the item, and the buyer takes it and pays the price. Jurists have differed regarding the validity of a sale through mu'atah. The majority consider it valid, while the Shafi'is prohibited it due to the absence of a verbal formula indicating consent. The majority, however, believe that mu'atah indicates consent and is supported by custom and common practice. The preponderant opinion is the permissibility of selling through mu'atah, due to the absence of explicit evidence stipulating verbal expression, and because it facilitates matters for people and is established by custom.