Take thou also unto thee wheat - In times of scarcity, it is customary in all countries to mix several kinds of coarser grain with the finer, to make it last the longer. This mashlin, which the prophet is commanded to take, of wheat, barley, beans, lentiles, millet, and fitches, was intended to show how scarce the necessaries of life should be during the siege.
Two things are prefigured in the remainder of this chapter,
(1) the hardships of exile,
(2) the straitness of a siege.
To the people of Israel, separated from the rest of the nations as holy, it was a leading feature in the calamities of their exile that they must be mixed up with other nations, and eat of their food, which to the Jews was a defilement (compare Ezekiel 4:13; Amos 7:17; Daniel 1:8.)
Fitches - A species of wheat with shorn ears.
In one vessel - To mix all these varied seeds was an indication that the people were no longer in their own land, where precautions against such mixing of seeds were prescribed.
Three hundred and ninety days - The days of Israel‘s punishment; because here is a figure of the exile which concerns all the tribes, not of the siege which concerns Judah alone.