Dedicating the Levites for service in the Tabernacle was a complex public event that required precise teamwork and deep emotional acceptance from every part of the nation. Rather than everyone performing the exact same action, each group fulfilled a highly specific and unique role [רש״י, אבן עזרא, מזרחי, גור אריה, שפתי חכמים].
Moses was responsible for positioning the Levites [רש״י, רבנו בחיי], guiding them with moral instruction to uplift their spirits [העמק דבר]. Some suggest he even took part in the physical process of shaving their hair [צפנת פענח]. Aaron, meanwhile, oversaw the sacrifices and the physical lifting of the Levites [העמק דבר]. This process required Aaron to lift every single one of the twenty-two thousand Levites off the ground in a single day. Accomplishing this monumental task required either immense physical strength or a miracle, reflecting his unique combination of strength and mercy [רבנו בחיי].
The Israelites also had distinct responsibilities. The primary approach among commentators is that they laid their hands upon the Levites, effectively appointing Aaron as their messenger [העמק דבר, חזקוני]. Another perspective suggests they took an active, hands-on role in the physical preparations, such as helping the Levites shave, washing their clothes, and bringing the sacrifices, rushing to complete these tasks to fulfill God's will [ספורנו].
The successful completion of this event brings special praise to everyone involved, particularly highlighting a specific group within the nation: the firstborns. Even though the privilege of working in the Tabernacle was taken from them and given to the Levites, they overcame their natural human instincts. They held no grudges and carried out the process with joy and exactness [אור החיים].
This massive public agreement required profound humility. By placing their hands on the Levites, the Israelites essentially confessed to the sin of the Golden Calf. They accepted that the firstborns had lost their special status and embraced the Levites as their spiritual stand-ins to bring them atonement. Anyone could have easily been angry or resistant, yet no one delayed the process [נחל קדומים]. The people accepted the Levites' new, elevated status without feeling any insult to their own honor, even though the Levites had previously lived among them as ordinary equals [העמק דבר]. The Levites themselves also earned great praise, stepping into their new roles with complete willingness. They did not complain or feel slighted that the redemption money collected from the extra firstborns was given to Aaron rather than to them [נחל קדומים].