The Grand Lodge of Saxony was one of the first association of free masons in Germany to open its doors to the kingdom`s Jewish residents in 1831. This resulted in relationships that also played out when the synagogue of the Jewish religious community was built by Gottfried Semper (1803–1879) in 1838/1840. The architect`s honorary, apparently modest at 500 thalers, was generously rewarded by the Jewish banker Martin Oppenheim with a second, private commission. The juxtaposition of Jewish and Islamic symbolism in the ornamentation inside the synagogue appears inexplicable and mysterious, fact which is underlined by the use of Islamic lettering. Even if this takes on a non-significant form, it can arouse astonishment. The occurrence of both Jewish and Islamic ornaments inside the synagogue can be explained by Semper`s interest in global art and culture. As a Freemason, he did not divide these two ornamental possibilities apart, but saw them as one of an overall view as an “oriental language of form”. Our hypothesis is to explain the juxtaposition of Jewish and Islamic symbols and lettering with Semper`s broad intellectual horizon, a spirit that was cultivated in the free masonic lodge “To the three swords and Astraea to the greening branch” in Dresden. This also made it possible for him to be in contact with Jewish lodge brothers. In this sense, the good understanding and interacting of the Freemason Semper with the Jewish religious community can be understood as a significant contribution to the integration of the Jews in Dresden which ended up with the construction of the synagogue.