What burden? Septuagint, Vulgate, and Rashi, read "Ye yourselves are the burden". Compare Jeremiah 23:36.
forsake. reject.
Related Commentaries of Jeremiah 23:33
Jeremiah 23:33
33 And when this people, or the prophet, or a priest, shall ask thee, saying, What is the burden of the LORD? thou shalt then say unto them, What burden? I will even forsake you, saith the LORD.