John Gill Commentary Jeremiah 17:20

"and say unto them, Hear ye the word of Jehovah, ye kings of Judah, and all Judah, and all the inhabitants of Jerusalem, that enter in by these gates:" — Jeremiah 17:20 (ASV)

And say unto them, hear you the word of the Lord
Concerning the sanctification of the sabbath; for this was not of human, but of divine institution:

you kings of Judah ;
which must be understood either, as Kimchi thinks, of the then present king and his sons, so called because they would reign after him; for, there was but one king at a time; and who, perhaps, at this time, was Josiah: or else the king and his nobles, the princes of the land, are meant:

and all Judah and all the inhabitants of Jerusalem, that enter in by
these gates ;
the people in the several parts of the land of Judea, that came to Jerusalem either for trade and merchandise, or for worship, and all that dwelt in the metropolis; for the business the prophet had to charge them with concerned them all.