XII.3.8
VIII. GLORIOUS KING FLAVIUS ERVIG
A Jew shall not marry a person nearly related to him by blood, or contract marriage without the benediction of a priest.
[...] The following, moreover, we direct shall be carefully observed in every respect, namely: that if any Jew, of either sex, after being converted, should desire to marry, he or she shall not be allowed to do so, unless a dowry is given, and a marriage contract entered into, as has been prescribed in the case of Christians; nor shall such ceremony be permitted, where it is not accompanied with the sacerdotal benediction within the bosom of the Church. [...]
There follows a passage on punishments on persons who have married in a wrongful manner.
(trans. P.S.Scott 1910: 388-389)