Midrasch zu Divrej Hajamim II 34:4

Rabbi Nathaniel said: Three hundred years before the birth of Josiah, was his name mentioned, as it is said, "Behold, a child shall be born unto the house of David, Josiah by name" (1 Kings 13:2); "And he was eight years old when he began to reign" (2 Kings 22:1). What is the disposition of a lad of eight years of age? He despised the idols and broke in pieces the pillars, and smashed the images and cut down the groves. His merit was great before the Throne of Glory. Because of the evil which Israel did in secret the righteous one was gathered (to his fathers), as it is said, "For the righteous is taken away because of the evil" (Isa. 57:1). || All Judah gathered together also with Jeremiah the prophet to show loving-kindness to Josiah, as it is said, "And Jeremiah lamented for Josiah, and all the singing men and the singing women spake of Josiah" (2 Chron. 35:25). Rabbi Meir said: "The singing men" refer to the Levites, who stood upon the platform singing; "and the singing women" refer to their wives. Rabbi Simeon said: These terms do not refer merely to the Levites and their wives; but to the skilled women, as it is said, "Thus saith the Lord of hosts, Consider ye, and call for the mourning women, that they may come; and send for the cunning women, that they may come: and let them make haste, and take up a wailing for us" (Jer. 9:17, 18). Hence the wise men instituted (the rule) that this should be done to all the wise men of Israel and to their great men, as it is said, "And they made them an ordinance in Israel" (2 Chron. 35:25).