Isaiah 8:4 - Ellicott's Commentary On The Whole Bible

For before the child shall have knowledge to cry... — Here then was another sign like that of Isaiah 7:14-16. The two witnesses of Isaiah 8:2 were probably summoned to the circumcision and naming of the child, and the mysterious name at which all Jerusalem had gazed with wonder was given to the new-born infant. The prediction is even more definite than before. Before the first cries of childhood (Heb. Abi, Ami) should be uttered, i.e., within a year of its birth, the spoils of the two capitals of the kings of the confederate armies should be carried to the king of Assyria. The conclusion of the period thus defined would coincide more or less closely with the longer period assigned at an earlier date (Isaiah 7:16). Historically the trans-Jordanic region and Damascus fell before Tiglath-pilneser; Samaria, besieged by Salmaneser, before his successor Sargon (2 Kings 15:29; 2 Kings 16:9; 2 Kings 17:6).