Adam Clarke's Bible Commentary Verse 3. Put not your trust in princes ] This nay refer, as has been stated above, to Cyrus, who had revoked his edict for the rebuilding of Jerusalem.
Perhaps they had begun to suppose that they were about to owe their deliverance to the Persian king. God permitted this change in the disposition of the king, to teach them the vanity of confidence in men, and the necessity of trusting in himself.
Matthew Henry Commentary
Verses 1-4 - If it is our delight to praise the Lord while we live, we shal certainly praise him to all eternity. With this glorious prospect before us, how low do worldly pursuits seem! There is a Son of man i whom there is help, even him who is also the Son of God, who will no fail those that trust in him. But all other sons of men are like the man from whom they sprung, who, being in honour, did not abide. God ha given the earth to the children of men, but there is great strivin about it. Yet, after a while, no part of the earth will be their own except that in which their dead bodies are laid. And when man return to his earth, in that very day all his plans and designs vanish and ar gone: what then comes of expectations from him?
Original Hebrew אל408 תבטחו982 בנדיבים5081 בבן1121 אדם120 שׁאין369 לו תשׁועה׃8668