Ibn Taymiyyah, may Allah have mercy on him, because transactions are not acts of worship in which a person is bound by what has been transmitted in the texts. Rather, they are dealings between people: whatever people regard as a sale is a sale; whatever they regard as a pledge is a pledge; whatever they regard as an endowment is an endowment; and whatever they regard as a marriage is a marriage.
The correct view, therefore, is that no contract has prescribed formulas; rather, contracts are concluded by whatever indicates them. No one can establish a distinction between a sale and other contracts. If they say, for example, “Allah mentioned marriage using the term marriage,” we say: Allah also mentioned sale using the term sale. Do you then say that one must say, “I have sold”? They say: This is not a condition. Thus, it is concluded by any wording that customarily indicates it, through an offer and an acceptance following it.
His statement, “and before it”: that is, it is also valid for the acceptance to precede it, but only in certain cases. These cases must indicate the contract. For example, someone may say, “Sell me such-and-such for ten,” and the seller replies, “I have sold it to you.” Here, that which indicates acceptance preceded the offer, but we have established the principle that a contract is concluded by whatever indicates it.
If someone says, “Will you sell me such-and-such for such-and-such?” and the other replies, “I have sold it to you,” is the contract concluded? The answer is that it is not. So, after he says, “I have sold it to you,” the other must say, “I accept.” This is why al-Rawd (1) states: “By an imperative expression or a past-tense expression unaccompanied by an interrogative or the like,” because the intended meaning is thereby conveyed. Thus, if he says, “I bought such-and-such from you for such-and-such,” and the other replies, “I have sold it to you,” the contract is concluded, because this indicates that the man has accepted. Therefore, acceptance may precede the offer on condition that it indicates it. But if it does not indicate it—such as when it is phrased in the present tense as a question, “Will you sell me such-and-such?” or “Are you selling me such-and-such?” or the like—then this is not regarded as a valid acceptance.