A.T. Robertson Commentary 2 Corinthians 9:12

"For the ministration of this service not only filleth up the measure of the wants of the saints, but aboundeth also through many thanksgivings unto God;" — 2 Corinthians 9:12 (ASV)

Service (λειτουργιας). Old word from λεως (people, λαος), λειτος like δημοσιος, public, and εργον, work. So public service either in worship to God (Luke 1:23) or benefaction to others (2 Corinthians 9:12). Our word liturgy is this word.

Filleth up (εστιν προσαναπληρουσα). Present active periphrastic indicative of double compound verb προσαναπληροω, Koine word, here and 11:9 only in N.T., to fill up by adding to. The Corinthians simply added to the total from others.

Unto God (τω θεω). Dative case and with a certain suddenness as at close of verse 11, really a parenthesis between in the somewhat tangled sentence.