A.T. Robertson Commentary Mark 6:13

"And they cast out many demons, and anointed with oil many that were sick, and healed them." — Mark 6:13 (ASV)

They cast out many demons and they anointed with oil (εξεβαλλον κα ηλειφον ελαιω). Imperfect tenses, continued repetition. Alone in Mark. This is the only example in the N.T. of αλειφω ελαιω used in connection with healing save in Jas 5:14. In both cases it is possible that the use of oil (olive oil) as a medicine is the basis of the practice. See Lu 10:34 for pouring oil and wine upon the wounds. It was the best medicine of the ancients and was used internally and externally. It was employed often after bathing. The papyri give a number of examples of it. The only problem is whether αλειφω in Mark and James is used wholly in a ritualistic and ceremonial sense or partly as medicine and partly as a symbol of divine healing. The very word αλειφω can be translated rub or anoint without any ceremony. "Traces of a ritual use of the unction of the sick appear first among Gnostic practices of the second century" (Swete). We have today, as in the first century, God and medicine. God through nature does the real healing when we use medicine and the doctor.