Aaron and his sons having now been solemnly consecrated to the priestly office by the ceremonies of seven days, their formal assumption of their daily duties in the tabernacle was marked by a special service suited to the august occasion, signalised at its close by the appearance of the glory of Jehovah to assembled Israel, in token of His sanction and approval of all that had been done. It would appear that the daily burnt-offering and meal-offering had been indeed offered before this, from the time that the tabernacle had been set up; in which service, however, Moses had thus far officiated. But now that Aaron and his sons were consecrated, it was most fitting that a service should thus be ordered which should be a complete exhibition of the order of sacrifice as it had now been given by the Lord, and serve, for Aaron and his sons in all after time, as a practical model of the manner in which the divinely-given law of sacrifice should be carried out. The order of the day began with a very impressive lesson of the inadequacy of the blood of beasts to take away sin. For seven consecutive days a bullock had been offered for Aaron and his sons, and so far as served the typical purpose, their consecration was complete. But still Aaron and his sons needed expiating blood; for before they could offer the sacrifices of the day for the people, they are ordered yet again first of all to offer a sin-offering for themselves. We read (vv. 1, 2): "And it came to pass on the eighth day, that Moses called Aaron and his sons, and the elders of Israel; and he said unto Aaron, Take thee a bull calf for a sin offering, and a ram for a burnt offering, without blemish, and offer them before the Lord." And then Aaron was commanded (vv. 3-5): "Unto the children of Israel thou shalt speak, saying, Take ye a he-goat for a sin offering; and a calf and a lamb, both of the first year, without blemish, for a burnt offering; and an ox and a ram for peace offerings, to sacrifice before the Lord; and a meal offering mingled with oil: for to-day the Lord appeareth unto you. And they brought that which Moses commanded before the tent of meeting: and all the congregation drew near and stood before the Lord."