The Scofield Bible Commentary, by Cyrus Ingerson Scofield, [1917], at sacred-texts.com
confederacy
The reference is to the attempt to terrify Judah by the confederacy between Syria and Samaria. (Isa 7:1); (Isa 7:2).
signs
The primary application here is to the two sons of Isaiah, "Maher-shalal-hash-baz", means "haste ye, haste ye to the spoil," a "sign" of the coming judgment of the captivity of Judah; "Shear-jashub", means "a remnant shall return," a "sign" of the return of a remnant of Judah at the end of the seventy years, (Jer 25:11); (Jer 25:12); (Dan 9:2). The larger and final reference is to our Lord (Heb 2:13); (Heb 2:14).