Exodus 29:1-4

“This is what you shall do to consecrate Aaron and his sons so that they may serve Me as priests: take one young bull and two rams, without blemish, and unleavened bread and unleavened cakes mixed with oil, and unleavened wafers spread with oil; you shall make them of fine wheat flour. You shall put them in one basket, and present them in the basket along with the bull and the two rams. Then bring Aaron and his sons to the doorway of the Tent of Meeting [out where the basin is] and wash them with water.