A.T. Robertson Commentary Titus 3:10

"A factious man after a first and second admonition refuse;" — Titus 3:10 (ASV)

Heretical (αιρετικον). Old adjective from αιρεσις (αιρεομα, to choose), a choosing of a party (sect, Acts 5:17) or of teaching (2 Peter 2:1). Possibly a schism had been started here in Crete.

Refuse (παραιτου). Present middle imperative of παραιτεω, to ask from, to beg off from. See same form in 1 Timothy 4:7; 5:11. Possibly an allusion here to Christ's directions in Mt 18:15-17.