an important book comparing the Rhodian Sea Law with Islamic maritime law as reflected in Islamic fatwās and in the Arabic Kitāb akriyat al-sufūn wa,’l-nizā‘ bayna ahlihā (“Treatise Concerning the Leasing of Ships and the Claims Between [Contracting] Parties”), Hassan Khalilieh argues that these rules from the late Roman Empire were mediated into Islam by local, Greek-speaking non-Muslims and “Islamicized” to conform with Qur’ānic and prophetic principles.32 An example from Islamic maritime law would be the requirement that all shippers share in losses incurred when jettisoning cargo.33
The regulation in the Talmud that apportionment of loss among the travelers should be determined by weight and not by the monetary value of the jettisoned items addresses one of the basic issues in ancient and medieval legal discussions of jettison, though in Justinian’s Digest and in virtually all medieval laws of jettison, the preference is for calculation by monetary value rather than by weight. Logically, weight was the primary consideration at the moment of jettisoning, though monetary value took center stage when merchants came to settle accounts later on.34 In a parallel halakha, the Palestinian Talmud (Bava Meṣi‘a 6:4, Venice edition 11a) stipulates that apportionment of loss is by both weight and value, evidently reflecting the dual consideration that operated in cases of jettison.35
The great diversity of rulings on jettison in ancient and medieval legal sources led Olivia Constable to surmise that “they must have reflected local practice and a common understanding of the basic principles of general average.” She illustrates this with diverse opinions in Islamic maritime laws about how to assign value to goods cast overboard.36 The Talmudic statement “they must not deviate from the custom of the mariners,” supports her assumption that customs varied from place to place and shows that, in the absence of halakhot covering maritime law, the rabbis of the Talmud and, in this respect, Maimonides as well, recognized and enforced customary practice current in the surrounding society.37 This precedent later informed the halakhic “policy” recognizing non-Jewish shipboard law when Jewish merchants traveled with their goods on ships owned by non-Jews, usually Muslims.38
With the coming of Islam, many new commercial customs came to the fore that required juristic attention and accommodation in the halakha. This process was begun relatively early by the Geonim, chiefly by granting commercial customs practiced in the Islamicate marketplace the force of law, exemplified by their legalization of the suftaja.39 Maimonides, who inherited the legal tradition of the Geonim and of his teachers in al-Andalus, expanded on the foundation laid by his predecessors, carrying their work of responding to the realities of the marketplace to a new level of attainment through the process of codification in the Mishneh Torah.
2.4 The Custom of the Merchants in Maimonides’ Code
Maimonides is likely to have been exposed to the custom of the merchants already during his youth, growing up in the commercial milieu of Muslim Spain and North Africa.40 Upon his arrival in Egypt, as we know from Ibn al-Qifṭī, he was engaged in trade in precious gems.41 He was intimately familiar with merchant custom from his India trader brother and from the legal queries about merchant activities that he regularly received. It should come as no surprise, therefore, to find Maimonides acknowledging and giving normative standing to the custom of the merchants in his Code.
A key text marking the place of merchant custom in the Code is found in the lead halakha of chapter 5 of Hilkhot sheluḥin ve-shutafim (Laws of Agents and Partners). Notably, however, the codifier does not use the phrase “custom of the merchants.” Here, as elsewhere in the Code, for the custom of the merchants, he uses the Hebrew phrase minhag ha-medina, literally, “custom of the land” or “local custom,” a locution that occurs in the Mishna, the Tosefta, and the Talmuds in relation to both ritual and civil law. He might have employed a neologism, minhag ha-soḥarim, translating the Gaonic term ḥukm al-tujjār and parallel to his own use of minhag ha-sappanim. His choice of the old, Tannaitic Hebrew expression minhag ha-medina suggests that he wished to anchor the custom of the merchants in his own time to the ancient halakha.
If a person forms a partnership with another without indicating stipulations [bi-stam], he may not deviate from local custom [minhag ha-medina] as regards that kind of merchandise. Nor may he travel to another place, or form a partnership with others with the same kind of merchandise, or deposit it with others as a bailment, or trade in any other merchandise. He shall not sell on credit except that which it is always the custom to sell on credit—unless [both partners] stipulated this at the outset or [the itinerant partner] acted with the other’s knowledge. If he deviates and acts without the other’s knowledge and afterwards tells him “I did such-and-such” and [the stationary partner] consents to this, then the former is not held liable. None of these matters requires ratification by qinyan. Oral agreement alone is sufficient.
The standard commentators could find no precise source for this halakha in its entirety in a classical rabbinic text. For the statement “or trade in any other merchandise,” R. Joseph Caro (d. 1575 in Safed, Palestine) in his Kesef Mishneh, one of the major commentaries on Maimonides’ Code, cites a baraita in the Tosefta (Bava Meṣi‘a 4:12 in the Lieberman edition), which is also cited by R. Isaac Alfasi in his epitome of the Talmudic tractate Bava Meṣi‘a. The core text in the Mishna (Bava Meṣi‘a 4:5) concerns a person hired to tend a shop. If he is a craftsman, the Tosefta adds, he should not practice his craft while on duty, lest he fail to pay attention to the customers. In Beit Yosef, Caro’s commentary on another great work of codification, the Tur, by Jacob b. Asher (d. 1340 in Toledo, Spain) (Hoshen Mishpaṭ 176:10), the author speculates that Maimonides is analogizing from that case to a partner, who should devote all his attention to the partnership at hand, lest he be distracted by other business. In fact, as we know from the Geniza letters, merchants dealt in a myriad of different types of merchandise, often merchandise belonging to partnerships that they held at one and the same time with different merchants, and it was easy to lose track.
The topic sentence, “If a person forms a partnership with another without indicating stipulations, he may not deviate from local custom [minhag ha-medina, lit., “custom of the city or region”] as regards that kind of merchandise,” warrants special attention. It calls to mind a principle expressed in Islamic jurisprudence with respect to hire: “Whatever is not stipulated explicitly [ghayra mashrūṭ] in the contract is treated in accordance with the custom of each city.”42
The phrase “local custom” (minhag ha-medina) is, indeed, key to contextualizing the halakha in question. It reflects aspects of everyday commercial practice in the Islamic world known to us from the Geniza and other Jewish sources from the Islamic period, particularly business arrangements concluded without drawing up formal, written contracts, which will be discussed in detail in chapters to come. The final sentence in the halakha makes this explicit: “Oral agreement alone is sufficient.”
The phrase “[n]or may he travel to another place … unless [both partners] stipulated this at the outset or [the partner in question] acted with the other’s knowledge” reflects the concern expressed in many Geniza letters or contracts and in a responsum of R. Isaac Alfasi that partners or agents keep to their prescribed itinerary, and it resonates with geographical restrictions that could be imposed upon an active party in an Islamic commenda, a type of business collaboration that we will discuss in Chapter 5.43 Violation of an agreement about trading destinations, along with infringement of other conditions, often ended up in court or on the desk of a jurisconsult like Maimonides. One of his responsa, for instance, describes a dispute that arose in a commenda, called by its Arabic name, muḍāraba, in the query. The active merchant was supposed to proceed to a certain city, sell the merchandise belonging to the stationary investor, take his portion of the profit, and turn the capital sum plus the investor’s earnings over
