2 Timothy 4:2

Preach--literally, "proclaim as a herald." The term for the discourses in the synagogue was daraschoth; the corresponding Greek term (implying dialectial style, dialogue, and discussion, Act 17:2, Act 17:18; Act 18:4, Act 18:19) is applied in Acts to discourses in the Christian Church. JUSTIN MARTYR [Apology, 2], describes the order of public worship, "On Sunday all meet and the writings of the apostles and prophets are read; then the president delivers a discourse; after this all stand up and pray; then there is offered bread and wine and water; the president likewise prays and gives thanks, and the people solemnly assent, saying, Amen." The bishops and presbyters had the right and duty to preach, but they sometimes called on deacons, and even laymen, to preach. EUSEBIUS [Ecclesiastical History, 6.19]; in this the Church imitated the synagogue (Luk 4:17-22; Act 13:15-16). be instant--that is, urgent, earnest, in the whole work of the ministry. in season, out of season--that is, at all seasons; whether they regard your speaking as seasonable or unseasonable. "Just as the fountains, though none may draw from them, still flow on; and the rivers, though none drink of them, still run; so must we do all on our part in speaking, though none give heed to us" [CHRYSOSTOM, Homily, 30, vol. 5., p. 221].

— Jamieson-Fausset-Brown Commentary (public domain)