2 Chronicles 28:20

And Tilgath-pilneser king of Assyria came unto him, and distressed him, but strengthened him not.

Tilgath-pilneser ... distressed him, but strengthened him not - i:e., notwithstanding the temporary relief which Tilgath-pilneser afforded him by the conquest of Damascus and the slaughter of Rezin (2 Kings 16:9), little advantage resulted from it, because Tilgath-pilneser spent the winter in voluptuous revelry at Damascus; and the connection formed with the Assyrian king was eventually a source of new and greater calamities and humiliation to the kingdom of Judah (2 Chronicles 28:2). 'The expression, "distressed him, but strengthened him not," should probably be understood simply of the exhausting effects of the tribute payments, and not of any failure of the Assyrian king to perform his compact relating to the Syro-Israelite invasion.

The silence of the Chronicles as to the aid given on that occasion is remarkable, and not easy to explain. Possibly the chronicler deemed it but of little worth, seeing that, after all, it had proved unable to save either Ahaz from further transgression or his kingdom from the hostile inroads of his bitterest enemies' (Vance Smith, 'Prophecies relating to the Assyrians,' p. 27). The unhappy case of Judah, after Ahaz had invoked the aid of the Assyrians, is paralleled in our early history by the Britons invoking the Saxons against the Scots and Picts. The Saxons did come and help them in repelling the northern invaders, but they remained masters of the country.