On the first Pentecost (or Shavuot [שׁבעות], the Feast of Weeks) after Jesus’ resurrection, the Holy Spirit visits the Jesus-followers in Jerusalem: “When the day of Pentecost arrived, they were all together in one place. And suddenly there came from heaven a sound of a mighty rushing wind… and divided tongues as of fire appeared to them and rested on each of them” (Acts 2:1-3). Of all the ways that God could have shown divine power on Pentecost, why “tongues” of fire? The most obvious reason is that these tongues lead to the disciples speaking in “other tongues” (Acts 2:4), but the imagery has precedent prior to this Pentecost. The Hebrew Bible refers to God’s consuming fire as “tongues,” and other Jewish literature before the New Testament describes tongues of fire in the heavenly realm. Therefore, it is fitting for these fiery tongues to appear on Pentecost as a manifestation of God’s holiness on earth.
The notion of heavenly tongues of fire appears first in Israel’s Scriptures. In response to the peoples’ waywardness, the prophet Isaiah declares, “As a tongue of fire (לשׁון אשׁ; lishon eish) devours the stubble, and as dry grass sinks down in the flame, so [Israel’s] root will be as rottenness, and their blossom go up like dust; for they have rejected the Law of the Lord of hosts” (Isa 5:24). This prophetic poetry suggests that just as a tongue of fire would lick at the dry ground to start a conflagration, so will God visit the people of Israel as a purging fire.
Isaiah’s reference to a single tongue of fire reappears as multiplied fiery entities in the Second Temple text of 1 Enoch (c. 300-200 BCE). Insofar as Genesis notes that Enoch “was no more for God took him” (Gen 5:24), later Jewish readers assumed that the Lord had taken Enoch to heaven, and they compiled various narratives about the biblical figure’s apocalyptic visions. Speaking of his heavenly tour, Enoch explains, “I approached a wall which was built of white marble and surrounded by tongues of fire… and I came into the tongues of fire and drew near to a great house…. And behold there was an opening before me: a second house which is greater than the firmer and everything was built with tongues of fire” (1 En 14:9-10, 15). This apocalyptic passage describes God’s heavenly Temples consisting of tongues of fire. Equipped with this background, the reader of Acts can see that the “tongues as of fire” (γλῶσσαι ὡσεὶ πυρός; glossai hosei puros) that arrive on Pentecost are the building blocks of God’s Temple in heaven—the divine structure on which the earthly Temples in Jerusalem were patterned. These tongues of fire are pieces of God’s dwelling place. God dwells in the Temple (both on earth and in heaven) and the fiery arrival of the Holy Spirit underscores the Lord’s continued dwelling among the followers of Jesus.