Beha'aloschaAharon is taught the method for kindling the Menorah. Moshe sanctifies the Levi'im to work in the Mishkan. They replace the firstborn, who were disqualified after sinning with the golden calf. After five years of training, the Levi'im serve in the Mishkan from ages 30 to 50; afterwards they engage in less strenuous work.
One year after the Exodus from Egypt, HaShem commands Moshe concerning the Korban Pesach. Those ineligible for the Korban Pesach request a remedy, and thus is given the mitsvah of Pesach Sheni, which allows a 'second chance' to offer the Korban Pesach one month later.