2 Kings 15:35
Howbeit the high places were not removed: the people sacrificed and burned incense still in the high places. He built the higher gate of the house of the Lord.
Cross-reference
2 Kings 15:4 shows the same failure to remove high places was true of Uzziah, echoing Jotham.
2 Kings 18:4 records Hezekiah removing high places, contrasting with Jotham's failure to do so.
In 2 Kings 14:4, the same phrase 'high places were not removed' describes Amaziah's reign — a recurring pattern of incomplete reform in Judah.
2 Chronicles 27:3-9 parallels Jotham's building of the upper gate and overall reign in more detail.
2 Chronicles 32:12 highlights Hezekiah's removal of high places, opposite to Jotham's inaction.
In 2 Chronicles 27:2, Jotham's reign is summarized similarly — he did right but the people still acted corruptly, though it adds he didn't enter the temple.
1 Kings 3:3 shows Solomon also sacrificed at high places, a recurring issue in Judah's kings.
In Isaiah 65:7, burning incense on mountains is condemned as iniquity — connecting to the persistent high place worship mentioned here.
In Ezekiel 9:2, the 'higher gate' is where judgment begins in a vision — possibly the same gate Jotham built.