For, behold, I will send serpents, cockatrices, among you, which will not be charmed, and they shall bite you, saith the LORD. I will send serpents - These were symbols of the enemies that were coming against them; a foe that would rather slay them and destroy the land than get booty and ransom.
Related Commentaries of Jeremiah 8:17
Jeremiah 8:17
17 For, behold, I will send serpents, cockatrices, among you, which will not be charmed, and they shall bite you, saith the LORD.