In Germany they frequently murdered the Jews, because the Christian people claimed (and provided good evidence) that the Jews spread the plague by poisoning the wells with whatever came to hand: spiders webs, lizards, toads and, most commonly, the severed heads of Christians. Not only had the Jews killed Jesus Christ, but during Holy Week it was common practice for them to re-enact this crime and kill a Christian child in order that they might draw out the fresh blood and knead some of it into the unleavened bread which they ate during their own Easter celebration, known as Passover. Their feast was designed to celebrate the moment in their history when they claimed that the Red Sea turned into blood and destroyed the Egyptian army, hence their need for fresh blood. However, this murderous act also demonstrated their hatred of Christianity. At the moment at which they stabbed the innocent Christian child, the Jews were known to recite the words: 'Even as we condemned the Christ to a shameful death, so let us also condemn this innocent Christian, so that, uniting the Lord and His servant in a like punishment, we may retort upon them the pain of that reproach which they impute to us.' In addition to using this blood in the preparation of bread, it was widely known that the Jews used fresh Christian blood for anointing rabbis, for circumcision, in stopping menstrual and other bleedings, in removing bodily odours, in making love potions and magical powder, and in painting the bodies of their dead.
Although the Venetian Grand Council sought to discourage the propagation of false ideas about the Jews (for these people were an important part of the republic's economy), the doge's inner Council of Ten nevertheless passed a law according to which the Jews were instructed to distinguish themselves by yellow stitching on their clothes. People detested the Jews for a variety of reasons, but the most often cited referred to their position in society as people who would loan money at an interest, more often than not requiring extravagant security from the borrower. To comprehend fully how shameful a trade this was, one had to understand that Christians were strictly forbidden to give out loans at interest to anyone. In fact, even Jews were forbidden by God Himself, taken from the word of the Scripture, to lend money to their 'brothers'. However, by interpreting this edict liberally, the Jews discovered that they could give loans to Christians, who were technically not their 'brothers', at whatever interest they deemed applicable. By obliging the Jews to lend money in exchange for permission to live in their territory, the Republic of Venice could pretend to be implementing a policy of some tolerance towards the Jews, while serving its own interests and ignoring the fact that it was further exposing the Jews to the multiple dangers of Christian hostility.
The grandparents of Portobuffole's principal Jewish moneylenders, Servadio and Moses, had begun to practise usury in Germany. Jews were unable to practise in either the arts or trades, no matter how skilled, for the various guilds had been deliberately established with religious affiliations to Christianity. Usury, however, because it was forbidden to Christians, remained a professional outlet for the Jews. The work was risky, and therefore profitable, but it was not physically demanding and it left time for both reading and studying. The Jews paid an excessive amount of tax on their profits, but plenty remained for them to live on. There was, however, little for them to invest in, so their money remained liquid, which further drove home the notion of the Jews maintaining a sybaritic lifestyle.
The Jewish moneylender offered to the public an indispensable service. In Portobuffole there was not a single working family who, every now and then, did not have to take out a loan in order to survive periods of poverty. However, a dependency upon the Jews was not confined to any one section of society. After the war with the Turks, the economy of the Most Serene Republic of Venice began to falter as the opportunity for expansion in the Orient appeared to have been blocked. This led young Venetian aristocrats to begin to explore the commercial and economic prospects inland, but only with the understanding that the Jews would be able to provide large-scale capital investment. However, despite their central role in Venetian society, Jews were ever-mindful that every debtor was a potential enemy, and that the goodwill of the usurer often fed the greediness of the borrower. It remained both easy and convenient for individuals habitually to accuse the Jews of wicked doing, and subsequently to confiscate their profits, but the doge and his Council of Ten realized that they could not afford to alienate these Jews completely.
The 'Contract of Moses' was the means by which the Jews were allowed 'freedom' to practise usury, but under strict controls. Whenever a town such as Portobuffole decided to grant a usurer's licence to a Jew, the contract between them, which was generally valid for five years and was renewable, had to be submitted to the Venetian Grand Council for ratification. The contract clearly listed the rights of the Jew proprietors and their collaborators:
— The Jews have usury rights (sometimes exclusively) in the town for the period valid in the contract.
— The Jews can live the way that they please and erect a synagogue.
— The Jews are not obliged to keep the banks open on Saturdays, or during other Jewish holidays.
— The Jews can refuse to lend to foreigners.
— The Jews can sell securities that have not been claimed for more than one year.
— The Jews are not held responsible for securities that are lost during fire, war, looting or robberies, or for securities that are gnawed by moths or rats (provided they keep cats in their houses).
— The Jews have the right to receive, from the butcher, living animals for the same price paid by Christians.
With as much care and precision, the 'Contract of Moses' listed the duties of the Jew proprietors and their collaborators:
— The Jews cannot keep banks open on Sundays, or on Christmas, Easter or Corpus Christi Day, or during any of the four feast days set aside for Mary.
— The Jews cannot refuse to lend money on securities with a value of less than ten ducati.
— If the Jews refuse to do this for more than ten consecutive workdays, then they have to pay a fine of ten ducati.
— The interest on their Jewish loans cannot exceed two and a half Venetian lire each month.
— In the case of loans given without securities, or, in other words, written loans, the monthly interest can rise to four lire.
— The Jews have to give loans up to one hundred ducati to the municipal government without interest.
— It is prohibited to take sacred furniture as a security; loans for weapons are given at the discretion of the Jew.
— A half of any fine is to be given to the town council.