Fausset's Bible Dictionary
'eets shemen (Isaiah 41:19), but in KJV Nehemiah 8:15 "pine branches." Probably the zackum or Βalanites Αegyptiaca is meant. Distinct from the zayit , "olive tree." The zackum is a small tree abundant in the Jordan plain. It is found all the way from India to Syria, Abyssinia, and the Niger. The zackum oil is highly esteemed by the Arabs as a remedy for wounds.
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Fausset, Andrew R. Entry for 'Oil Tree'. Fausset's Bible Dictionary. https://www.studylight.org/dictionaries/eng/fbd/o/oil-tree.html. 1949.