The substitution of the Levites for the firstborn of every family was an intricate system of service and redemption. The firstborn of all the famillies of Israel numbered 22, 273. The number of the Levites was 22,000. The extra 273 people had to be redeemed for God by an offering of five shekels. The 273 were redeemed by an offering to the Levites that totaled 1365 shekels. Their livestock was also given to God as a substitute for all the firstborn of the livestock of Israel. I am not certain how they determined who who need to be redeemed by the five shekel offering, but it is pretty certain that a particular system of numbering was employed. Suggestion are that they were numbered chronologically, by age, or either by family according to the birth order of the father. Either way, the substition was determined and all the firstborn were redeemed. This was a hearkening back to the Passover, when God spared all the firstborn of Israel and took the firstborn of Egypt. From that day, the firstborn were considered consecrated to God.
The duties of the Levites are laid in in further detail in this passage. The Kohathites are described first, as they are called to cover, protect, and transport the ark of the covenant, considered the place where the presence of God dwelt, the furniture and utensils of the holy place, and other untensils of the tabernacle. This was a highly sensitive and important role for the Kohathites, as they were under danger of death if they did not handle the ark properly. We must handle the presence of God with care and holiness today. Perhaps we are not going to fall over dead if we mishandle the presence of God. Perhaps we are. Either way, God’s presence is not to be taken lightly, but with reverence and appreciation. Cover the presence of God and walk with Him in awe and reverence!