Ezekiel 4:9
Take thou also unto thee wheat, and barley, and beans, and lentiles, and millet, and fitches, and put them in one vessel, and make thee bread thereof, according to the number of the days that thou shalt lie upon thy side, three hundred and ninety days shalt thou eat thereof.
Cross-reference
Ezekiel 4:5 assigns the 390 days as representing Israel's years of iniquity — the same timeframe for eating the mixed grain in v9.
Ezekiel 4:13 reveals that this mixed-grain bread symbolizes unclean food Israel will eat in exile — the instruction in v9 enacts that judgment.
Ezekiel 4:16 describes the actual famine in Jerusalem with bread eaten by weight — Ezekiel's symbolic eating in v9 prefigures that scarcity.
Ezekiel 4:6 assigns 40 days for Judah's iniquity — complementing the 390 days for Israel in v9 as part of the same symbolic act.
2 Kings 25:3 records the severe famine during Jerusalem's siege — Ezekiel's ration in v9 foreshadows this historical food shortage.
Jeremiah 52:6 records the same siege famine as 2 Kings 25:3 — Ezekiel's measured bread in v9 prefigures this historic scarcity.