1 Corinthians 6:6
“But brother goes to law with brother, and that before unbelievers.”
The charge is twofold; both that he “goes to law,” and “before the unbelievers.” For if even the thing by itself, To go to law with a brother, be a fault, to do it also before aliens, what pardon does it admit of?
Source: Homilies on First Corinthians (New Advent)