Isaiah 7:4-6, 14

and say to him: ‘Take heed, and be quiet; do not fear or be fainthearted for these two stubs of smoking firebrands, for the fierce anger of Rezin and Syria, and the son of Remaliah. Because Syria, Ephraim, and the son of Remaliah have plotted evil against you, saying, “Let us go up against Judah and trouble it, and let us make a gap in its wall for ourselves, and set a king over them, the son of Tabel”

Therefore the Lord Himself will give you a sign: Behold, the virgin shall conceive and bear a Son, and shall call His name Immanuel.