As we consider the anointing oil of Exodus 30 it is good to note that the oil is to be used in temple service only and that it is a sacred anointing oil. The application of this oil to the tent, the ark, and every article of furniture or utensil which is used in the temple seems to intimate that without something extra and special applied to worship it would remain unacceptable. Every person in service and every article must be anointed with the oil.
What can this refer to other than the work of the Holy Spirit. It is the Spirit who prays for us. it is the Spirit who applies the work of Christ to our life and makes us holy. It is the Spirit who reminds us of the teachings of Christ and who makes our actions worthy of presentation to the Father. The Holy Spirit is our anointing oil.
In 1Samuel 16:13 we find this association most closely declared.
So Samuel took the horn of oil and anointed him in the presence of his brothers, and from that day on the Spirit of the LORD came upon David in power. Samuel then went to Ramah.
In fact, Jesus declares that it is the very Spirit of God that has anointed him and prepared him for the special work of God.
The Spirit of the Lord is on me, because he has anointed me to preach good news to the poor. He has sent me to proclaim freedom for the prisoners and recovery of sight for the blind, to release the oppressed, (Luke 4:18)
And as believers this anointing also rest upon us and makes us holy and acceptable to God.
Now it is God who makes both us and you stand firm in Christ. He anointedus, set his seal of ownership on us, and put his Spirit in our hearts as a deposit, guaranteeing what is to come. (2Corinthians 1:21-22)
But you have an anointing from the Holy One, and all of you know the truth… As for you, the anointing you received from him remains in you, and you do not need anyone to teach you. But as his anointing teaches you about all things and as that anointing is real, not counterfeit — just as it has taught you, remain in him. (1John 2:20, 27)