A.T. Robertson Commentary Revelation 2:16

"Repent therefore; or else I come to thee quickly, and I will make war against them with the sword of my mouth." — Revelation 2:16 (ASV)

Repent therefore (μετανοησον ουν). First aorist (tense of urgency) active imperative of μετανοεω with the inferential particle ουν (as a result of their sin).

I come (ερχομα). Futuristic present middle indicative, "I am coming" (imminent), as in 2:5 with ταχυ as in 3:11; 11:14; 22:7,12,20. As with εν ταχε (1:1), we do not know how soon "quickly" is meant to be understood. But it is a real threat.

Against them (μετ' αυτων). This proposition with πολεμεω rather than κατα (against) is common in the LXX, but in the N.T. only in Re 2:16; 12:7; 13:4; 17:14 and the verb itself nowhere else in N.T. except Jas 4:2. "An eternal roll of thunder from the throne" (Renan). "The glorified Christ is in this book a Warrior, who fights with the sharp sword of the word" (Swete).

With (εν). Instrumental use of εν. For the language see 1:16; 2:12; 19:15.