'Act' in the Bible

This is the anointing of Aaron, and the anointing of his sons out of the fire-offerings of Jehovah, in the day he hath brought them near to act as priest to Jehovah,

'And the priest whom he doth anoint, and whose hand he doth consecrate to act as priest instead of his father, hath made atonement, and hath put on the linen garments, the holy garments;