John Gill Commentary 2 Chronicles 32:9

"After this did Sennacherib king of Assyria send his servants to Jerusalem, (now he was before Lachish, and all his power with him,) unto Hezekiah king of Judah, and unto all Judah that were at Jerusalem, saying," — 2 Chronicles 32:9 (ASV)

After this did Sennacherib king of Assyria send his servants
to Jerusalem
Who are mentioned by name, (2 Kings 18:17) this was after Hezekiah had given him a large quantity of silver and gold to depart, and he did depart from him, (2 Kings 18:14–16)

but he himself laid siege against Lachish ,
and all his power with him; one of the cities of Judah, see (Isaiah 36:2) , from hence he dispatched them

unto Hezekiah king of Judah, and unto all Judah that were at Jerusalem ;
who had retired thither for safety, upon the invasion of their country by the king of Assyria.