John Calvin on 1 Corinthians 16:19

19. With the Church that is in their house A magnificent eulogium, inasmuch as the name of the Church is applied to a single family! At the same time it is befitting, that all the families of the pious should be regulated in such a manner as to be so many little Churches. As to the term Congregation, which Erasmus has used in preference, it is foreign to Paul’s design; for it was not his intention to designate a crowd of persons by a mere common term, but to speak in honorable terms of the management of a Christian household. His saluting them in the name of Aquila and Priscilla, confirms what I have noticed above — that the Epistle was written at Ephesus, not at Philippi. For Luke informs us, that they remained at Ephesus, when Paul went elsewhere. (Acts 18:19.)