'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 because Jehovah has anointed thee prince over his inheritance?

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

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