Bede, on Prov 18:19

“A brother that is helped by his brother, is like a strong city: and judgments are like the bars of cities.”

“A brother helped by a brother, etc. When both peoples, namely Jews and Gentiles, agree in fraternal charity in Christ, they now build a united city of the Catholic Church. And just as the bars fortify the gates of cities, so the doctrines of both Testaments defend the churches around the world, which make up the one Catholic Church, from the incursion of unbelievers.”

Imported from an open dataset — not yet checked against the printed edition.