PRIEST, (The function he served was superior to that of other priests)

=>To light the lamps of the tabernacle

Exodus 27:20-21

20. And thou shalt command the children of Israel, that they bring thee pure oil olive beaten for the light, to cause the lamp to burn always.

21. In the tabernacle of the congregation without the vail, which is before the testimony, Aaron and his sons shall order it from evening to morning before the LORD: it shall be a statute for ever unto their generations on the behalf of the children of Israel.

Exodus 30:8

8. And when Aaron lighteth the lamps at even, he shall burn incense upon it, a perpetual incense before the LORD throughout your generations.

Leviticus 24:3-4

3. Without the vail of the testimony, in the tabernacle of the congregation, shall Aaron order it from the evening unto the morning before the LORD continually: it shall be a statute for ever in your generations.

4. He shall order the lamps upon the pure candlestick before the LORD continually.

Numbers 8:3

3. And Aaron did so; he lighted the lamps thereof over against the candlestick, as the LORD commanded Moses.