'Oil' in the Bible

“O mountains of Gilboa,Let not dew or rain be upon you, nor fields with offerings;For there the shield of the mighty was defiled,The shield of Saul, [dry, cracked] not anointed with oil.

So Joab sent word to Tekoa and had a wise woman brought from there and told her, “Please pretend to be a mourner, and put on mourning clothes, and do not anoint yourself with oil, but act like a woman who has for many days been in mourning for the dead.