Zechariah 4:3 describes the two olive trees beside the lampstand, which the prophet asks about in 4:11. It provides the visual detail.

Zechariah 1:9 shows the same angelic dialogue pattern; here the prophet again asks about a vision's meaning.

Zechariah 1:19 also features the prophet asking 'What are these?' about the horns; here he asks about the olive trees.

Revelation 11:4 explicitly identifies the two witnesses as the two olive trees from Zechariah, fulfilling the Old Testament imagery.