Firebrand
A firebrand is a piece of burning wood — a torch or kindled stick that can be thrown, carried, or pulled out of a fire. The umbrella has one literal narrative use, in Samson's revenge against the Philistines, and three figurative uses: a proverb, a prophetic word from Amos, and Zechariah's vision of the high priest.
Samson's Foxes
The literal use is the only narrative case. "And Samson went and caught three hundred foxes, and took firebrands, and turned tail to tail, and put a firebrand in the midst between every two tails" (Jdg 15:4). Three hundred foxes are paired tail-to-tail, with a single firebrand fixed between each pair, so that the firebrand becomes the weapon by which Samson sets fire to the Philistine grain.
Figurative Uses
The book of Proverbs uses the firebrand as the picture of a person who deceives a neighbor and then claims it was a joke: "As a lunatic who casts firebrands, Arrows, and death," (Pr 26:18). The implements thrown by the lunatic — firebrand, arrow, the bringing of death — set up the comparison that the next verse completes.
Amos turns the image to Israel as a survivor pulled half-burnt from a fire. "[My Speech has] overthrown [cities] among you⁺, as when God overthrew Sodom and Gomorrah, and you⁺ were as a brand plucked out of the burning: yet you⁺ have not returned to me, says Yahweh" (Am 4:11). The brand "plucked out of the burning" pictures Israel as already on fire, already partially consumed, and rescued only at the last moment — yet still unwilling to return.
Zechariah uses the same image of rescue from fire in his vision of Joshua the high priest standing before the angel of Yahweh while Satan accuses him. "And Yahweh said to Satan, Yahweh rebuke you, O Satan; yes, Yahweh who has chosen Jerusalem rebuke you: is not this a brand plucked out of the fire?" (Zec 3:2). The rhetorical question puts the high priest in the same posture as Amos's Israel — rescued from burning, not yet wholly consumed — but as the ground for the rebuke of the accuser rather than as a reproach.