And saw an altar - Rather, this refers to “The altar,” that is, an Assyrian altar connected with the formal recognition of Assyrian deities …

Ahaz went to Damascus, to meet Tiglath-pileser. —The great king appears to have held his court there after the capture of the city…

And King Ahaz went to Damascus to meet Tiglathpileser king
of Assyria
When he heard he …

God's altar had until then been kept in its place and in use; but Ahaz put another to replace it. The natural human inclination toward some form of…