Matthew Poole and continuators on 2 Peter 3:1

1 THIS second epistle , beloved, I now write unto you, in both which I stir up your pure minds by way of remembrance .

This confirms what hath been said, That this Epistle was writ by Peter, as well as the former.

Or, sincere mind; the sense is either, 1. I stir up your Minds, that they may be pure, and sincere; and then he doth not so much commend them for what they were, as direct and exhort them to what they should be, that they might receive Benefit by what he writ, there being nothing that contributes more to the fruitful entertaining of the Word, than Sincerity, and honesty of Heart, when Men lay aside those things which are contrary to it, and might hinder its Efficacy, 1 Pet. 2.1, 2. Or, 2ly. I stir up your Minds, tho pure and sincere, to continuance and constancy in that pure Doctrine ye have received.

See chap. 1.13.