The expression, "Break up your fallow ground" (Hos. 10:12; Jer.
4:3) means, "Do not sow your seed among thorns", i.e., break off
all your evil habits; clear your hearts of weeds, in order that
they may be prepared for the seed of righteousness. Land was
allowed to lie fallow that it might become more fruitful; but
when in this condition, it soon became overgrown with thorns and
weeds. The cultivator of the soil was careful to "break up" his
fallow ground, i.e., to clear the field of weeds, before sowing
seed in it. So says the prophet, "Break off your evil ways,
repent of your sins, cease to do evil, and then the good seed of
the word will have room to grow and bear fruit."