King Ahaz of Judah is worried. His two rivals to the north, Rezin of Aram and Pekah of Israel had allied against him, probably to force him into their anti-Assyrian alliance. The whole nation is fearful, and their hearts are shaking like the “trees of the forest shake before the wind” (Isa. 7:2).
So, YHWH sends the prophet Isaiah to calm Ahaz’s nerves, telling Isaiah to talk trash about Rezin and Pekah: “Take heed, be quiet, do not fear, and do not let your heart be faint because of those two smoldering stumps of firebrands” (Isa. 7:4). Yes, I know, “smoldering stumps” loses something in translation (and in the Hebrew there’s no illiteration), but would you expect God to be an expert trash talker? We can at least give YHWH credit for picking up the tree imagery (stumps, shaking trees) from verse 2 (although that came from the narrator).
But isn’t trash talking supposed to be targeted directly at the insulted party? Usually, but not always. As we know from the world of modern sports, when a competitor insults his or her opponent indirectly, it often finds it’s way to their ears (now this happens through the news media). Trash talking has a dual purpose, to intimidate a foe and to encourage a friend (or oneself). Here, Ahab needs help. So, God tells him he doesn’t need to worry about Rezin and Pekah (they’re past their prime, they’ve shot their wad).
Encouragement for Ahaz is given another way. Interestingly, in this section Ahaz is twice referred to as “the house of David” (Isa. 7:2, 13), an allusion to the Davidic promise of an eternal ruling descendent on the throne of Israel (2 Sam. 7). So, in essence YHWH is saying, don’t worry about those two losers to the north, I’ve got you covered because you’re a son of David.
A few verses later (Isa. 7:14), YHWH also promises that a young woman (or virgin?) will give birth to a boy named “With-us-God” (Immanuel). As Matthew’s gospel informs us (1:23), the virgin birth/God-with-us theme fits nicely with the birth of Jesus, but a wait of over 700 years for Jesus wouldn’t be particularly encouraging for poor Ahaz who needs help now, so presumably the Immanuel prediction had an earlier fulfillment for Ahaz.
If it’s OK for God to trash talk I assume it’s OK for us, so when should we talk trash?