Literally, “in falsehood,” or “in deception.” Judah acted a lie in her pretended reformation.
Whole heart.
The reformation under Josiah (v. 6) was a mere outward turning to God. At heart the people still clung to their idols. After the king’s death they lapsed into open idolatry (2 Kings 23:31, 32; 2 Chron. 36:5-8).