rather, it is a restriction contingent upon a particular circumstance—namely, the absence of the condition. Once the permissibility of a contract has been established, the default is that no condition is required for it. For when we add a condition to the permissibility of a contract, this means that we prohibit that contract when the condition is absent. This entails that the contract is prohibited in some circumstances. So we say: Your prohibiting it when this condition is not met requires evidence. Accordingly, stipulating that the seed must be supplied by the landowner requires evidence.
The affirmative evidence is that the Messenger of Allah ﷺ entered into an arrangement with the people of Khaybar for half of whatever it produced of fruit or crops (1), yet he did not provide them with the seed or the saplings. Had this been a condition, the Prophet ﷺ would have provided them with the seed and the saplings. Affirmative evidence is needed where the evidence itself is negative, both to strengthen the argument and to state it explicitly.
His statement, “and the saplings,” points to tree-sharing, which the author did not mention. There is a third type of contract besides orchard-sharing and sharecropping, known as tree-sharing; it is also called munāṣabah. This is when a person gives land to someone who plants trees on it and tends them in return for a share of the trees—not a share of their fruit, but a share of the planted trees themselves. The fruit follows the principal asset. The difference between this and orchard-sharing is that orchard-sharing grants a share of the fruit, while the trees themselves belong to the landowner. Tree-sharing, on the other hand, grants a share of the principal asset itself—that is, the trees. It is permissible. Once it is concluded, the worker is entitled to half or a quarter of the trees, according to the agreed condition. In orchard-sharing, once it is concluded, the worker is entitled to half or a quarter of the fruit, according to the agreed condition. Thus, there is a difference between them.