Canon 17 issued by the 9th Council of Toledo [Spain]: “17. Baptized Jews shall be present at Christian feast days as well as Jewish at the episcopal divine service, so that the bishop may see their fidelity. Whoever does not this shall be punished, according to his age, with blows or fasting.” [Editor’s Note: Author dates this council taking place in November 2, 655.]
“A History of the Councils of the Church, from the Original Documents. By the Right Rev. Charles Joseph Hefele…” Karl Joseph von Hefele. Volume 4. Page 473-474