Charles Ellicott Commentary 2 Kings 23:25

"And like unto him was there no king before him, that turned to Jehovah with all his heart, and with all his soul, and with all his might, according to all the law of Moses; neither after him arose there any like him." — 2 Kings 23:25 (ASV)

And like unto him was there no king before him. — Compare 2 Kings 18:5–6, where a similar eulogy is passed upon Hezekiah. It is not, perhaps, necessary to insist upon any formal contradiction which may appear to result from a comparison of the two passages. A writer would not be careful to measure his words by the rule of strict proportion in such cases. Still, as the preceding account indicates, the Mosaic law does not appear to have been so rigorously carried out by any preceding king as by Josiah. (See Note on 2 Chronicles 30:26.)

With all his heart ... — An echo of Deuteronomy 6:5. That Josiah’s merits did not merely consist in a strict observance of the legitimate worship and ritual, is evident from Jeremiah 22:15-16, where he is praised for his righteousness as a judge.