At the departure, however, from Egypt, it was declared that all the firstborn were specially sanctified to God in token of the mercy shown to them there (Ex. xiii. 2), and when Moses received the Divine commands concerning the construction of the Tabernacle, it was ordered that from the children of Israel Aaron and his sons should be specially selected _to minister in the priests’ office_ (Ex. xxviii. 1). Subsequently, when the whole tribe of Levi displayed such signal zeal on the occasion of the construction of the golden calf (Ex. xxxii. 26), that tribe was separated for the service of the sanctuary, and accepted in the place of the firstborn, as the royal guard to wait on Israel’s King (Num. i. 47–54; iii. 5–13). But though the whole tribe was set apart for these important purposes, a strictly prescribed order regulated its particular functions to each branch, of which there were three, (a) THE LEVITES, (b) THE PRIESTS, (c) THE HIGH-PRIEST. (a) _The Levites_ entered on their duties at the age of 30 (Num. iv. 23, 30, 35), and were consecrated, not as the priests, by anointing and investiture, but by a ceremony of washing accompanied by sacrifices, after which the elders laid their hands upon them, and Aaron presented them _as a wave-offering before the Lord_, in token that they were offered to the Lord by the congregation for the service of the sanctuary, and handed over by Him to the Priests[84]. Thus occupying a middle place between the people, who were all ideally _a kingdom of priests_, and the higher sacerdotal orders, they might approach nearer to the Tabernacle than the other tribes, but they might not offer sacrifice, nor burn incense, nor handle the holy vessels of the Sanctuary, till they were concealed from view (Num. iv. 15). The Levites, then, were _the assistants of the priests_, and consisted of three families or sections, the sons of GERSHON, KOHATH, and MERARI. i. The _Kohathites_ held the first rank, as being the family to which Aaron belonged. It was their duty, on the removal of the Tabernacle, to bear all the sacred vessels, including the Ark itself, but not before the priests had concealed them from the profane gaze with a dark blue pall (Num. iii. 31; iv. 6, 9, 15; Deut. xxxi. 25). ii. The _Gershonites_ were charged with the removal of the curtains, veils, and tent-hangings (Num. iv. 22–26). iii. To the _Merarites_ was entrusted the heavier portion of the Tabernacle furniture, such as the boards, pillars, and bars, and therefore with the Gershonites they were permitted to use the oxen and waggons contributed by the congregation, while the Kohathites were only suffered to remove the sacred vessels on their shoulders (Num. vii. 1–9). With this arrangement agreed their position in the encampment in the wilderness. While the place of honour on the east was occupied by the sons of Aaron, the Kohathites were on the south, the Gershonites on the west, the Merarites on the north.