It's A Glad Anointing

Psalm 45:7 New English Translation (NET Bible)

7 You love justice and hate evil.

For this reason God, your God has anointed you

with the oil of joy, elevating you above your companions.

Isaiah 61:3 New International Version (NIV)

3     and provide for those who grieve in Zion—

to bestow on them a crown of beauty

    instead of ashes,

the oil of joy

    instead of mourning,

and a garment of praise

    instead of a spirit of despair.

They will be called oaks of righteousness,

    a planting of the Lord

    for the display of his splendor.

In Acts 13:52 we read, "The disciples were filled with joy and with the Holy Ghost." Wherever he comes as an anointing, whether upon the Lord or upon his people, upon the Christ or the Christians, upon the Anointed or upon those whom he anoints, in every case the ultimate result is joy and peace. On the head of our great High Priest he is joy, and this oil of gladness flows down to the skirts of his garments. To the Comforter, therefore, we ascribe "the oil of gladness."
Charles Spurgeon