These things have I written - Either meaning the whole epistle, or what is contained in the preceding verses, from the beginning of the 18th to the end of the 25th.
Them that seduce you - Περι των πλανωντων ὑμας· That is, the deceivers that were among them, and who were labouring to pervert the followers of Christ.
These things have I written unto you concerning them that seduce you - Respecting their character, and in order to guard you against their arts. The word “seduce” means to lead astray; and it here refers to those who would seduce them “from the truth,” or lead them into dangerous error. The apostle does not mean that they had actually seduced them, for he states in the following verse that they were yet safe; but he refers to the fact that there was danger that they might be led into error.