Charles Ellicott Commentary Jeremiah 4:3

"For thus saith Jehovah to the men of Judah and to Jerusalem, Break up your fallow ground, and sow not among thorns." — Jeremiah 4:3 (ASV)

For thus says the Lord ... —The words seem to be the close of one discourse and the opening of another. The parable of Israel is left behind, and the appeal to Judah and Jerusalem is more direct.

To the men of Judah. —Literally, to each man individually.

Break up your fallow ground. —The Hebrew has the force that comes from the verb and noun being from the same root: Break up for yourselves a broken ground or fallow a fallow field. The metaphor had been used before by Hosea (Hosea 10:12). What the spiritual field needed was to be exposed to God’s sun and God’s free air, to the influences of spiritual light and warmth, and to the dew and soft showers of His grace.

Sow not among thorns. —Not without special interest as, perhaps, containing the germ of the Parable of the Sower in Matthew 13:7. Here, as there, the seed is the word of God, spoken by the prophet and taking root in the heart, and the thorns are the cares of this world—the selfish desires that choke the good seed and render it unfruitful.