2. Chronik 34:3

Extirpation of idolatry. In the eighth year of his reign, while he was yet a youth, being then only sixteen years old, Josiah began to seek the God of his ancestor David, and in the twelfth year of his reign he commenced to purify Judah and Jerusalem from the high places, Asherim, etc. The cleansing of the land of Judah from the numerous objects of idolatry is summarily described in Ch2 34:4 and Ch2 34:5; and thereupon there follows (Ch2 34:6 and Ch2 34:7) the destruction of the idolatrous altars and images in the land of Israel, - all that it seemed necessary to say on that subject being thus mentioned at once. For that all this was not accomplished in the twelfth year is clear from the לטהר החל, "he commenced to cleanse," and is moreover attested by Ch2 34:33. The description of this destruction of the various objects of idolatry is rhetorically expressed, only carved and cast images being mentioned, besides the altars of the high places and the Asherim, without the enumeration of the different kings of idolatry which we find in 2 Kings 23:4-20. - On Ch2 34:4, cf. Ch2 31:1. ינתּציּ, they pulled down before him, i.e., under his eye, or his oversight, the altars of the Baals (these are the בּמות, Ch2 34:3); and the sun-pillars (cf. Ch2 14:4) which stood upwards, i.e., above, upon the altars, he caused to be hewn away from them (מעליהם); the Asherim (pillars and trees of Asherah) and the carved and molten images to be broken and ground (הדק, cf. Ch2 15:16), and (the dust of them) to be strewn upon the graves (of those) who had sacrificed to them. הזּבחים is connected directly with הקּברים, so that the actions of those buried in them are poetically attributed to the graves. In Kg2 23:6 this is said only of the ashes of the Asherah statue which was burnt, while here it is…

Before we see Judah and Jerusalem ruined we shall yet see some glorious years, while good Josiah sits at the helm. By his pious endeavours for reformation God tried them yet once more; if they had known in this their day, the day of their visitation, the things that belonged to their peace and improved them, their ruin might have been prevented. But after this reign they were hidden from their eyes, and the next reigns brought an utter desolation upon them. In this chapter we have, I. A general account of Josiah's character (Ch2 34:1, Ch2 34:2). II. His zeal to root out idolatry (Ch2 34:3-7). III. His care to repair the temple (Ch2 34:8-13). IV. The finding of the book of the law and the good use made of it (Ch2 34:14-28). V. The public reading of the law to the people and their renewing their covenant with God thereupon (Ch2 34:29-33). Much of this we had 2 Kings 22.

34:3 Josiah began to seek the God of his ancestor David when he was just sixteen. He initiated his own acts of reform when he reached age twenty.