Charles Ellicott Commentary 2 Kings 18:22

"But if ye say unto me, We trust in Jehovah our God; is not that he, whose high places and whose altars Hezekiah hath taken away, and hath said to Judah and to Jerusalem, Ye shall worship before this altar in Jerusalem?" — 2 Kings 18:22 (ASV)

But if ye say. —The address seems to turn abruptly from Hezekiah to his ministers, and to the garrison of Jerusalem in general. But the Septuagint, Syriac, Arabic, and Isaiah 36:7 have the singular, “But if thou say,” which is probably original. (Hezekiah is currently mentioned in the third person to avoid ambiguity.)

In the Lord our God. —The emphatic words of the clause.

Whose high places and whose altars Hezekiah hath taken away. —This is just the construction which a heathen would naturally put on Hezekiah’s abolition of the local sanctuaries (2 Kings 18:4; 2 Chronicles 31:1). The Assyrians would appear to have heard of Hezekiah’s reformation. Since he was a vassal of the great king, his proceedings were undoubtedly watched with jealous interest.

Ye shall worship ... in Jerusalem? —Literally, Before this altar shall you worship, at Jerusalem. The great altar of burnt offering was to be the one altar, and Jerusalem the one city, where Jehovah might be worshipped.