בִּשְׁנַת־מ֖וֹת הַמֶּ֣לֶךְ אָחָ֑ז הָיָ֖ה הַמַּשָּׂ֥א הַזֶּֽה׃
In the year that king Ahaz died was this burden.
Rashi on Isaiah
In the year of King Ahaz’s death and his son Hezekiah reigned, was this harsh prophecy concerning the Philistines given.
Ibn Ezra on Isaiah
המשא.27Here a new chapter commences, according to I. E. The prophecy28A. V., Burden. or a parable in the prophetic style, as is apparent from the words For out of the serpent’s root, etc.