Passage
Then the word of Yahweh came to Jeremiah, saying,
Then the word of Yahweh came to Jeremiah, saying,
Jeremiah 33:17 For thus says Yahweh, ‘David shall not have a man cut off from sitting on the throne of the house of Israel;
Jeremiah 33:18 and the Levitical priests shall not have a man cut off from before Me who is to offer burnt offerings, to offer up grain offerings in smoke, and to perform sacrifices continually.’”
Jeremiah 33:19 Then the word of Yahweh came to Jeremiah, saying,
Jeremiah 33:20 “Thus says Yahweh, ‘If you can break My covenant for the day and My covenant for the night, so that day and night will not be at their appointed time,
Jeremiah 33:21 then My covenant may also be broken with David My servant so that he will not have a son to reign on his throne, and with the Levitical priests, My ministers.
The verse centers on "word", "yahweh", "came", "jeremiah", and "saying". It is saying that the verse draws attention to "word" and "yahweh", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 18's "and the Levitical priests shall not have..." into verse 20's "Thus says Yahweh If you can break...", so "word" and "yahweh" belong inside that flow. In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "word" and "yahweh" with trust shaped by these words, not by a vague optimism outside the passage.