And the altars that were on the top (roof) of the upper chamber of Ahaz. — The roof of an upper chamber in one of the Temple courts. perhaps built over one of the gateways (comp. Jeremiah 35:4), appears to be meant. The altars were for star-worship, which was especially practised on housetops. (Comp. Jeremiah 19:13; Jeremiah 32:29; Zephaniah 1:5.)
Brake them down from thence. — The Targum has removed from thence; the LXX. pulled them down from thence (κατέσπασεν). The Hebrew probably means ran from thence; marking the haste with which the work was done. The clause thus adds a vivid touch to the narrative. It is hardly necessary to alter the points with Kimchi and Thenius, so as to read, he caused to run from thence; i.e., hurried them away.
Cast the dust of them. — Over the wall of the Temple enclosure, into the ravine beneath.