Prior to his elevation to the rectorate he was a produce-merchant; and the Talmud preserves an anecdote of that time which affords an insight into the economic laws of the age as well as an idea of Dimi's standing among the learned even in his youth. The law had provided that—except the dealer in spices or perfumes at any time, and the public generally while fairs were being held—no non-resident merchant might enter his wares in competition with local traders. A notable exception to this rule was the scholar. To him the market was always open; and to facilitate his sales and his return to study, the law gave him the rights of monopoly until he disposed of his goods. Now, Dimi once brought to Mahuza a shipload of dried figs, when Rava was requested by the exilarch "to tap Dimi's pitcher", i.e., to examine him ascertain whether he was a scholar and consequently entitled to the special market privileges. Rava deputed Adda bar Abba (Ahaba) to examine Dimi; and Adda propounded to the newcomer a supposititious ritual question. Dimi thought that his interlocutor was Rava himself, and deferentially inquired, "Is not my master Rava?" The other, familiarly tapping him on the sandal, replied, "Between me and Rava there is a great difference. At any rate, I am your superior, and Rava is your superior's superior." The privileges of the market were not granted to Dimi, and eventually the figs spoiled. He then applied to Rav Yosef for redress; and the latter, provoked at the discomfiture of the scholar, exclaimed, "He who has not failed to avenge the disgrace of the Edomite king will not fail to avenge your disgrace." It is added that shortly afterward Rab Adda died suddenly, and several rabbis, including Dimi, who had some grievances against him, reproached themselves with having been indirectly instrumental in his punishment. As an educator Dimi acted on the maxim, "Rivalry among scholars advances scholarship"; therefore he approved Rava's rule not to remove a teacher because his rival makes better progress with his pupils, arguing that rivalry will induce more strenuous efforts and produce better results. On the other hand, Rava, believing that "mistakes will correct themselves," showed preference for the teacher that succeeded in imparting much knowledge, even if not very exact. Dimi opposed this with his maxim, "Where error has once crept in, it stays"; and he therefore looked