Matthew Poole and continuators on 1 Kings 18:40

40 And Elijah said unto them , Take the prophets of Baal, let not one of them escape: and they took them, and Elijah brought them down to the brook Kishon , and slew them there .

He takes the opportunity, whilst the peoples hearts were warm with the fresh sense of this great miracle.

That their blood might be poured into that River, and thence conveyed into the Sea, and might not defile the Holy Land.

Quest. How could Elijah do this, seeing he was but a private Person? Ans. First, He had no doubt the consent of all the heads of the People, who were here assembled; and of the King too, who durst not resist the universal torrent, and could not deny that they were Impostors, and worthy of Death; and probably was by the Prophet assured of Rain when this was done. Ans. Secondly, As these Idolatrous Priests were manifestly under a Sentence of Death, passed upon such by the Sovereign Lord of Life and Death, Deut. 13. and 17. so Elijah had sufficient Authority to execure it, as being a Prophet, and an extraordinary Minister of Gods vengeance against sinners, now especially when the Magistrate so grosly neglected his Duty therein.

Marginal references: Or, apprehend.