en_tn_condensed/act/15/21.md

Moses has been proclaimed in every city ... and he is preached in the synagogues every Sabbath

James is implying that Gentiles know how important these rules are because Jews preach them in every city where there is a synagogue. It also implies the Gentiles can go to the teachers from the synagogues to learn more about these rules.

Moses has been proclaimed ... he is preached

"The law of Moses has been proclaimed ... the law is read" or "Jews have taught the law of Moses ... they read the law"

in every city

"in many cities"