ישעיהו, פרק כ׳, פסוק א׳

As the Assyrian empire rises and expands its military conquests, the people of Judah grow afraid and are tempted to look south, seeking alliances with Egypt and Cush for protection. To prevent this mistake, God sends a clear warning early on: these southern powers will also fall to Assyria, making any reliance on them completely useless [מצודת דוד, שד״ל].

The campaign begins when an Assyrian army commander—holding the military title of Tartan [ביאור שטיינזלץ]—is dispatched to the Philistine city of Ashdod [אבן עזרא, שד״ל]. Ashdod is targeted because it is a heavily fortified city in the south, near the border of Egypt, and perhaps even under Egyptian control. Taking Ashdod is a strategic necessity, serving as a stepping stone for Assyria's broader war against Egypt [שד״ל].

There are different views regarding exactly when this campaign takes place. One perspective places these events in the fourteenth year of King Hezekiah's rule, coinciding with the year the Assyrian army marches on Jerusalem before turning its attention to Egypt and Cush [רד״ק]. Other commentators argue that the siege of Ashdod actually begins three years prior to the Assyrian advance on Jerusalem [מלבי״ם, רד״ק]. Regardless of the exact year, the prophecy is delivered to Isaiah as soon as the Assyrian commander arrives at Ashdod. The actual fall of the city happens much later, marking the end of a difficult siege that likely lasts three years [שד״ל].

The leadership behind this campaign presents an interesting historical question regarding the identity of Sargon, the king of Assyria. The primary approach among commentators, drawing on early rabbinic tradition, identifies Sargon as simply another name for the well-known King Sennacherib. Conversely, some suggest that Sargon is an entirely distinct ruler [אבן עזרא]. According to this view, Sargon reigns between Shalmaneser and Sennacherib. This would mean the prophecy is given earlier in Isaiah's life, as Sennacherib only takes power later during Hezekiah's era. If this is the case, the commander who leads the attack on Ashdod serves under Sargon and later continues his military duties as an older man during Sennacherib's reign [שד״ל, ביאור שטיינזלץ].