Leviticus 8:28

“You shall put them on Aaron your brother and on his sons with him; and you shall anoint them and ordain them and set them apart as holy, that they may minister to Me as priests.

“Now this is what you shall do to them to set them apart as holy to minister as priests to Me: take one bull from the herd and two rams without blemish,

“You shall gird them with sashes, Aaron and his sons, and bind caps on them, and they shall have the priesthood by a perpetual statute. So you shall ordain Aaron and his sons.

“You shall take them from their hands and offer them up in smoke on the altar on the burnt offering for a soothing aroma before Yahweh; it is an offering by fire to Yahweh.

Moses and Aaron were among His priests, And Samuel was among those who called on His name; They would call upon Yahweh and He would answer them.