Dora Bas Rivka Silver O'H
Half of It is Ego
This Psalm, according to its introduction, is to be accompanied on an instrument called the yedusun, which was only used in the Temple.
David says that his soul waits only for G-d, Who is the only source of strength and salvation. David knows that though he may slip, G-d will not let him fall.
David asks his enemies how long they'll plot against innocent people. They plot to murder him, but they will live in perpetual fear of their own imminent destruction, like walking under a wall that's about to collapse. They are desperate to destroy David before he can ascend to power and punish them. They are hypocrites, praising verbally while cursing him internally.
And so, David's soul waits for G-d's salvation, secure that he will not even slip. David knows for a fact that G-d will take care of all his needs; he encourages the nation to place their complete trust in G-d. David asks that they pour their hearts out in prayer to Him. If they humble themselves before Him, they will enjoy His salvation.
Mere humans are meaningless - they can neither harm nor help. Even seemingly important people are not so powerful as they'd have you believe. At least half of them is their over-inflated ego. Money won't get you far, and that goes double for ill-gotten gains. Oh, sure, it seems to have its uses, but it won't do any good when G-d decrees something against a person.
G-d has told us more than once that real power is His alone. Not only that, but mercy is His, as well. G-d gives each person what they deserve.