Isaiah 1:1

The vision of Isaiah ben Amoz, which he envisioned concerning Judah and Jerusalem, in the days of Uzziah, Jotham, Ahaz, and Hezekiah, kings of Judah.

Rashi: חזון ישעיהו בן אמוץ, etc. Rebbi Lêvi said (Megillo 10b): We have a tradition from our ancestors that 'Omôtz and 'Amatzyo King of Judah were brothers.

אשר חזה על יהודה וירושלים. But did he not prophesy about a number of nations? "The burden of Egypt" (Isaiah 19:1); "the burden of Babylonia" (Isaiah 13:1); "the burden of Moab" (Isaiah 15:1). Thus you learn that this is not the beginning of the book, and the book is not named after this vision. We learn this in a boraitho in the M^ekhilto (Shiro, B^eshallaḥ 7):

The beginning of the book is "In the year of King Uzziah's death..." (Isaiah 6:1), for there is no earlier or later in the sequence. The contents prove this, for on the day of The Earthquake, the day when Uzziah was afflicted with tzora`ath, [Isaiah] "heard the voice of the LORD saying: 'Whom shall I send, and who shall go forth for us?'; and I replied: 'Here I am, send me!'." (Isaiah 6:8) From this we can derive that [this event] must have been the beginning of his mission.

This prophecy [in chapter 1] was said only afterwards, and it is with respect to this prophecy alone that the verse says אשר חזה על יהודה וירושלים. Just as it reports about the burden of each and every nation "the burden of Nation X", so does it say here "he envisioned this vision with respect to Judah and Jerusalem".

Because [this chapter] consists of harsh statements of rebuke, it calls them חזון, which is the harshest of the ten expressions that refer to prophecy, as is stated in B^erêshith Rabbo (44:6); a proof-text for this is the verse חָזוּת קָשָׁה הֻגַּד לִי, "a harsh חזות was told to me" (Isaiah 21:2).

בימי עזיהו יותם אחז יחזקיהו מלכי יהודה. He outlived (קִיפֵּחַ, literally overpowered or buried) these four kings in his lifetime. On the day when Uzziah was stricken by tzora`ath (supernatural skin-disease), the Divine Presence first descended upon [Isaiah]; and he prophesied all the days of these kings, until Menasseh came along and killed [Isaiah].

Discussion question: What can we say about Rashi's use of the idiom קִיפֵּחַ to describe Isaiah's outliving of Uzziah, Jotham, Ahaz, and Hezekiah? And why is it necessary to say that Menasseh executed Isaiah? Remember, this detail appears nowhere in any biblical text. How does it help to elucidate this verse?