'Oil' in the Bible

Then Samuel took the vial of oil, and poured it upon his head, and kissed him, and said, Is it not that Jehovah hath anointed thee to be prince over his inheritance?

And Jehovah said unto Samuel, How long wilt thou mourn for Saul, seeing I have rejected him from being king over Israel? fill thy horn with oil, and go: I will send thee to Jesse the Beth-lehemite; for I have provided me a king among his sons.

Then Samuel took the horn of oil, and anointed him in the midst of his brethren: and the Spirit of Jehovah came mightily upon David from that day forward. So Samuel rose up, and went to Ramah.