It wasn't Jeremiah that was opposed to the Jews fleeing to Egypt. It was God. He pronounced his judgment and determined what he wanted to do. The Jews sought to escape God's judgment by fleeing to Egypt rather than being taken captive to Babylon. God had promised mercy in his judgment if the Jews would submit to him and go to Babylon. To disobey meant more than judgment, it was going to be wrath. That is why it is written, it is a fearful thing to fall into the hands of an angry God.

As a side note, it is a pattern throughout the Bible that God shows mercy and restraint in judgment, both Old and New Testaments. But, there is a time when enough is enough and the Potter smashes the clay.

It wasn't Jeremiah that was opposed to the Jews fleeing to Egypt. It was God. Jeremiah 42:10-12 God says through Jeremiah:

• stay in the land (Judah)
• Don't be afraid of the king of Babylon
• God would grant mercy and allow them to stay in their own land

However, if they refused and disobey the voice of the Lord, Jeremiah 42:13-22

• God would send the sword and it would overtake them
• Famine would get them
• Those that flee to Egypt shall die by the sword, by famine, and by pestilence and there will be no survivors (42:17).

The reason for this is that God has determined a time of wrath for the Jews (v42:18) for disobedience and he has promised mercy in his wrath if they obey (42:12)

But they refuse and will obey so they will perish (42:21-22)

So, it is not Jeremiah who is opposed, but God himself. God providing mercy in judgment is typical of his character as shown here, but it has to be done his way as also shown here to receive it. The latter is also typical of his character.