thou anointest my head with oil; my cup runneth over.
Psalm 23 Verse 5b
At the time when the psalm was written, if a person‘s head was anointed with oil it was to appoint them to a royal position. When the good shepherd puts oil on our head, he is showing us who we are for him. People with identity and authority that come from him. Everything we have comes from him. Including the strength to fulfil our purpose.