Sins are many times hid from the godly man's eye, though he commits them, because he is not diligent and accurate in making a search of himself, and in an impartial studying of his own ways. If any sin be hid, as Saul was behind the stuff, or as Rahab had hid the spies, unless a man be very careful to search, he shall think no sin is there where it is. Hence it is that the Scripture doth so often command that duty of searching and trying, of examining and communing with our hearts. Now what need were there of this duty, but that it is supposed many secret and subtle lusts lie lurking in our hearts, which we take no notice of? If then the godly would find out their hidden lusts, know the sins they not yet know, they must more impartially judge themselves; they must take time to survey and examine themselves; they must not in an overly and slight manner, but really and industriously look up and down as they would search for thieves; and they must again and again look into this dark corner, and that dark corner of their hearts, as the woman sought for the lost groat. This self scrutiny, and self judging, this winnowing and sifting of ourselves, is the only way to see what is chaff and what is wheat, what is mere refuse and what is enduring.