The next three verses (Jeremiah 8:10–12) are very similar to Jeremiah 6:12–15. These could very well be well-tried phrases that Jeremiah used, or some well-known material from preachers who had a message similar to that of Jeremiah.1
As in Jeremiah 6:12–15, when judgment comes in the form of the invading force from the north, the leaders of Judah will lose their wives and their land to the conquerors, along with everyone else. This judgment is coming because everyone, from the greatest to the least has become greedy for unjust gain. Judah has become a greedy and unjust nation. In particular, the religious leaders, the priests, and the prophets, who should have led the people out of their wickedness, are corrupt themselves. They also deal falsely.
10 Therefore I will give their wives to others and their fields to conquerors, because from the least to the greatest everyone is greedy for unjust gain; from prophet to priest, everyone deals falsely.