A.T. Robertson Commentary Romans 16:5

"and [salute] the church that is in their house. Salute Epaenetus my beloved, who is the first-fruits of Asia unto Christ." — Romans 16:5 (ASV)

The church that is in their house (την κατ' οικον αυτων εκκλησιαν). The early Christians had no church buildings. See also Ac 12:2; 1 Corinthians 16:19; Phm 1:2; Colossians 4:15. The Roman Christians had probably several such homes where they would meet.

Epainetus (Επαινετον). Nothing is known of him except this item, "the first-fruits of Asia" (απαρχη της Ασιας). An early convert from the province of Asia. Cf. Acts 2:9; 1 Corinthians 16:15 (about Stephanus and Achaia).