The End is NearBy Rabbi Jack Abramowitz
God told Moshe to get ready because his end was rapidly approaching. He had Moshe bring Yehoshua to the Mishkan, where He caused His Presence to manifest in the pillar of cloud.
God told Moshe that after he was gone, the nation would stray into idolatry. God will then “look away” and allow the Jews’ enemies to conquer them. They’ll ultimately realize that they brought this on themselves by alienating Him.
Moshe was commanded to write down the song that appears in parshas Ha’azinu and to teach it to the Jews. They should familiarize themselves with it because it would serve as a witness for them.