Psalms 64:5,6 - Joseph Benson’s Commentary on the Old and New Testaments

They encourage themselves Hebrew, יחזקו, jechazeku, they strengthen, or fortify themselves, by firm resolutions, by assured confidence of success, by uniting their counsels and forces together, and by mutual encouragements and exhortations. They say, Who shall see them Their snares are so secretly laid, that they think David cannot discern, nor therefore avoid them. They search out iniquities They study diligently and constantly to find out either matter which they may lay to my charge, or new ways and means of doing mischief. They accomplish a diligent search They have long and accurately searched, till at last they have ripened and perfected their thoughts, and contrived a very cunning and deep plot. Or, they say, We have accomplished our accurate search. By long searching we have at last found what we desired. And the heart is deep Deep as hell, desperately wicked, who can know it? By their unaccountable wickedness, they show themselves to be, both in subtlety and malignity, the genuine offspring of the old serpent.