of the whole church - (See Act 20:4). It would appear that he was one of only two persons whom Paul baptized with his own hand (compare 3Jo 1:1). His Christian hospitality appears to have been something uncommon.
Erastus the chamberlain - “treasurer.”
of the city - doubtless of Corinth. (See Act 19:22; 2Ti 4:20).
and Quartus a brother - rather, “the” or “our brother”; as Sosthenes and Timothy are called (1Co 1:1; 2Co 1:1, Greek). Nothing more is known of this Quartus.