Exodus 23:29

In one year. While men are impatient, God is long-suffering and wonderfully forbearing (2 Peter 3:9). The Canaanite nations would not be driven out all at once, lest (1) the land should become desolate, there not being enough people to care for it; (2) the beasts of the field should multiply and so become a danger. When the northern Hebrew kingdom of Israel was depopulated by the removal of the ten tribes into captivity, there was a marked increase of lions that preyed upon the scanty remnant (2 Kings 17:24, 25). In many districts of France wolves increased following the Franco-Prussian War. Another reason why the nations were not driven out immediately was that God desired to “prove” Israel to see whether they would obey Him (Judges 2:21–23).