Albert Barnes Commentary Zechariah 4:12

"And I answered the second time, and said unto him, What are these two olive-branches, which are beside the two golden spouts, that empty the golden [oil] out of themselves?" — Zechariah 4:12 (ASV)

What are the two spikes of the olive? - Comparing the extreme branches of the olive-tree, laden with their fruit, to the ears of corn, which “were by or in the hand of the golden pipes, which empty forth the golden oil from themselves.” Zechariah’s expression, in the hand of or, if so be, by the hand of the two pipes, shows that these two were symbols of living agents, for it is nowhere, used except of a living agent, or of that which it personified as such.