The olive comes from a blessed tree and Allah mentioned it seven times in the Quran.
Allah said: By the fig and the olive [Surah at-Teen:1]
Sheikh Abdulrahman as-Sadi (may Allah have mercy on him) said in explaning this Verse, “Allah swore by these two trees due to the immense benefit contained in these trees and likewise in their fruit.”
Allah said: Allah is the Light of the heavens and the earth. The parable of His Light is as a niche within it a lamp: The lamp is in a glass, the glass as it were a brilliant star, lit from a blessed tree, an olive, neither of the east nor of the west, but whose oil would almost glow forth, though no fire touched it. Light upon Light! [Surah al-Mo’min: 35]
Imam Ash-Shawkani (may Allah have mercy on him) mentioned in his tafseer collection Fathul Qadeer, that olive oil comes from a blessed tree as Allah mentions and that it also comes from a blessed land. He also mentioned that the Arabs used to use olive oil for their hair.
Allah said: He it is Who sends down water from the sky; from it you drink and from it (grows) the vegetation on which you send your cattle to pasture. With it He causes to grow for you the crops, the olives, the date-palms, the grapes, and every kind of fruit. Verily! In this is indeed an evident proof and a manifest sign for people who give thought. [Surah an-Nahl:10-11]
NOTE: There is a wealth of knowledge to be found on the medical benefits of Figs and olives and products derived from them like olive oil etc in terms of both dietary and cosmetic benefits.