Speaking lies in hypocrisy
Or "through the hypocrisy of those that speak lies"; for the apostle is still speaking of the means by which the apostasy should rise, and get ground; and it should be by the means of persons that should deliver lying or false doctrine under the colour of truth, and make great pretensions to religion and holiness, which would greatly take with men, and captivate and lead them aside: and this plainly points at the abettors of antichrist, the Romish priests, who deliver out the lying doctrines of merit, purgatory, invocation of saints, fastings, pilgrimages and the fabulous legends of saints, and the lying wonders and miracles done by them, and all under a show of godliness, and the promoting of religion and holiness:
having their conscience seared with a hot iron;
which exactly describes the above mentioned persons, whose consciences are cauterized and hardened, and past feeling; and have no regard to what they say or do, make no conscience of anything, but under a cloak of sanctity commit the most shocking impieties; and are men of the most infamous characters, and of the most enormous and scandalous lives and conversations; so that the metaphor may be taken either from the searing of flesh with an iron, or cauterizing it, whereby it grows callous and hard; or from the stigmas or marks which used to be put on malefactors, or such who have been guilty of notorious crimes.