the sale of unseen specific goods, whether described or not, on the interpretation that selling unseen goods involves contractual uncertainty even when they are described. He went so far as to require descriptions and precision concerning goods owed as an obligation—such as goods due under an advance-payment sale—that no other jurist required. Under such a position, transactions involving specific goods and goods owed become impossible or difficult for people.
He extended the rules governing sales involving contractual uncertainty by analogy to all contracts, whether gratuitous or involving an exchange. Thus, he imposed on a hired worker’s wages, compensation for a wife’s release from marriage, contractual manumission payments, settlements with parties to a truce, and the jizyah payable by non-Muslims under Muslim protection the same requirements that he imposed on sales involving specific goods or goods owed. In these matters, he permitted only such kinds, quantities and descriptions as he would permit in a sale, even though these contracts are not invalidated by defects in their consideration, or are subject to other conditions.
As for Abū Hanīfah, he permits the sale of broad beans and similar produce within both their coverings. He permits hiring a worker in return for food and clothing, and allows the bridal due to be unspecified to the same extent as the customary bridal due for a woman of comparable standing. He also permits the sale of unseen specific goods without a description, provided there is an option to rescind, because he recognizes that contracts may remain pending. Yet he categorically prohibits crop-sharing arrangements for tending orchards and cultivating land, and similar transactions.
Al-Shāfiʿī permits the sale of some of these things. He also prohibits many conditions in sales, leases, marriages and other contracts that depart from what an unqualified contract entails. Abū Hanīfah permits some of these conditions, as well as forms of agency and partnership that al-Shāfiʿī does not permit. He even permits mufāwadah partnerships and agency concerning wholly unspecified matters.