Revelation 2:9
I know your works, and tribulation, and poverty, (but you are rich) and I know the blasphemy of them which say they are Jews, and are not, but are the synagogue of Satan.
Nave's Topical Index—AKJV

Revelation 3:9
Behold, I will make them of the synagogue of Satan, which say they are Jews, and are not, but do lie; behold, I will make them to come and worship before your feet, and to know that I have loved you.
Nave's Topical Index—AKJV