Charles Ellicott Commentary Jeremiah 17:5

"Thus saith Jehovah: Cursed is the man that trusteth in man, and maketh flesh his arm, and whose heart departeth from Jehovah." — Jeremiah 17:5 (ASV)

Cursed be the man ... —The words are vehement and abrupt, but they burst from the prophet’s lips as proclaiming the root evil that had eaten into the life of his people. Their trust in an arm of flesh had led them to Egyptian and Assyrian alliances, and these to “departing from the Lord.” The anathema has its counterpart in the beatitude of Jeremiah 17:7. The opening words, Thus saith the Lord, indicate, perhaps, a pause, followed as if by a new message, which the prophet feels bound to deliver. It is significant that the prophet uses two words for the English “man”—the first implying strength, and the second, weakness.