וַיִּקְשְׁר֨וּ עָלָ֥יו קֶ֛שֶׁר בִּירוּשָׁלִַ֖ם וַיָּ֣נָס לָכִ֑ישָׁה וַיִּשְׁלְח֤וּ אַֽחֲרָיו֙ לָכִ֔ישָׁה וַיְמִתֻ֖הוּ שָֽׁם׃
And they made a conspiracy against him in Jerusalem; and he fled to Lachish; but they sent after him to Lachish, and slew him there.
Rashi on II Kings
They conspired a revolt against him, etc. Because they heard what the prophet said, “that God has made a plan to destroy you.”7Ibid. v. 16.
Rashi on II Kings
And he fled to Lakish. He was there for the entire fifteen years.