The Hebrew word is elah, and is supposed to be the terebinth, though it is often translated “oak.” In Isaiah 6:13 “the oak” (allon) is mentioned as well as the elah, different trees are therefore doubtless indicated by the two Hebrew words. It is now generally supposed that allon refers to the oak, and elah to the terebinth, the Pistacia terebinthus.
Pistacia Palaestina