On Holy Wednesday evening we anoint the faithful with oil for healing, to identify our mortal bodies with the death and Resurrection of Christ; with his stripes we are healed.
"Through the anointing of the sick body the sufferings of the person should be sanctified and united to the sufferings of Christ. In this way, the wounds of the flesh are consecrated, and strength is given that the suffering of the diseased person may not be unto the death of his soul, but for eternal salvation in the resurrection and life of the Kingdom of God." -- Fr. Thomas hopko
I lay not my sinful hand upon the head of him (her) who is come unto thee... but thy strong and mighty hand, which is in this, thy Holy Gospels, that is now held by my fellow-ministers, upon the head of thy servant... -- Service of Anointing
Read more about the Mystery of Anointing