Cursed be the man, &c.— This alludes to the confidence which the Jews had of assistance from the Egyptians, and their other allies, when threatened by the Chaldeans. By flesh is meant mere mortal man, in opposition to the Almighty; and by arm is meant power or confidence. See Isaiah 31:1 and Calmet.
Related Commentaries of Jeremiah 17:5
Jeremiah 17:5
5 Thus saith the LORD; Cursed be the man that trusteth in man, and maketh flesh his arm, and whose heart departeth from the LORD.