Secondly, on account of their dispersion through the world, which had its compensating advantages. United to their brethren by close fraternal ties, speaking a common tongue and moving frequently from place to place, the exchange of commodities was facilitated. Then having smaller opportunities of expenditure, and in any case of moderate tastes, they naturally possessed ready means.
Lastly, their hard fate in lands of exile, the growing precariousness of their position under fanatic powers, quickened their wits in the life struggle and endowed them with the capacities that earn success in trade. (We are not therefore surprised to learn that the Jews invented bills of exchange.)
This is all there was to justify the medieval belief in the colossal wealth of the Jews and the fantastic notions as to its acquisition.
Notes and References.
Slavery and the Jews:
The humanity of the Hebrew slave laws is one of the commonplaces of history. See Exodus xxi and Deut. xxiii.
The Slave Trade, chapter vi in Jewish Life in the Middle Ages, Abrahams, J. P. S. A.
Theme for discussion:
In what respect did medieval slavery differ from Russian serfdom and from the bond service in the early colonial era of America?