They encourage themselves - literally, they strengthen themselves, or make themselves strong. That is, they take counsel; they encourage each other; they urge one another forward; they suggest to each other methods by which what they purpose may be done, and by which difficulties may be overcome. This was a part of their “secret counsel” or their consultation, Psalms 64:2.
In an evil matter - Margin, as in Hebrew, speech. The reference is to their purpose or plan. They strengthen themselves for doing what they know to be a wrong or wicked thing.
They commune - literally, they tell or speak. That is, they tell each other how it may be done, or suggest different methods by which it may be successfully accomplishled. They compare views, that they may select that which will be most likely to be successful. All this indicates plan, consultation, design.
Of laying snares privily - Margin, as in Hebrew, to hide snares. This is a figure derived from the method of taking wild beasts. See Psalms 7:15, note; Psalms 38:12, note. The reference here is to some secret plan by which they intended that the author of the psalm should be entrapped and ruined. It was not a plan of open and manly warfare, but a purpose to destroy him when he would have no opportunity of defense.
They say, Who shall see them? - That is, who will see the snares or pit-falls? Who will be aware of their existence? They sought to make the plan so secret that no one could discover it, or even suspect it; to keep it so concealed that he for whom it was intended could not be put on his guard. Compare Psalms 10:8-9.