Put not your trust in princes - Rely on God rather than on man, however exalted he may be. There is a work of protection and salvation which no man, however exalted he may be, can perform for you; a work which God alone, who is the Maker of all things, and who never dies, can accomplish. See the notes at Psalms 118:8-9. Compare also the notes at Isaiah 2:22 : “Cease ye from man, whose breath is in his nostrils, for wherein is he to be accounted of?”
Nor in the son of man - Any son of man; any human being, no matter what his rank or power. The phrase is often used to denote man. See the notes at Psalms 8:4. The appellation “Son of man” was often applied by the Saviour to himself to express emphatically the idea that he was a man - that he had a human nature; that he was identified with the race; that he was a brother, a fellow-sufferer, a friend of man: that he was not a cold and abstract being so exalted that he could not feel or weep over the sins and woes of a fallen and suffering world. The language here, however, it is scarcely necessary to say, does not refer to him. It is right to put our trust in him; we have no other trust.
In whom there is no help - Margin, salvation. So the Hebrew. The idea is, that man cannot save us. He cannot save himself; he cannot save others.