If thou hast run with the footmen - If the smallest evils to which thou art exposed cause thee to make so many bitter complaints, how wilt thou feel when, in the course of thy prophetic ministry, thou shalt be exposed to much greater, from enemies much more powerful? Footmen may here be the symbol of common evil events; horsemen, of evils much more terrible. If thou have sunk under small difficulties, what wilt thou do when great ones come?
And if in the land of peace, wherein thou trustedst - I believe the meaning is this, "If in a country now enjoying peace thou scarcely thinkest thyself in safety, what wilt thou do in the swellings of Jordan? in the time when the enemy, like an overflowing torrent, shall deluge every part of the land?"
The overflowing of Jordan, which generally happened in harvest, drove the lions and other beasts of prey from their coverts among the bushes that lined its banks; who, spreading themselves through the country, made terrible havoc, slaying men, and carrying off the cattle.
Perhaps by footmen may be meant the Philistines, Edomites, etc., whose armies were composed principally of infantry; and by the horses, the Chaldeans, who had abundance of cavalry and chariots in their army. But still the words are proverbial, and the above is their meaning.
Yahweh rebukes Jeremiah‘s impatience, showing him by two proverbial sayings, that there were still greater trials of faith in store for him. Prosperous wickedness is after all a mere ordinary trial, a mere “running with the footmen;” he will have to exert far greater powers of endurance.
And if in the land - Rather, “and in a land of peace thou art secure; but how wilt thou do amid the pride of Jordan?” if thou canst feel safe only where things are tranquil, what wilt thou do in the hour of danger? The “pride of Jordan” is taken to, mean the luxuriant thickets along its banks, famous as the haunt of lions (compare Jeremiah 49:19; Jeremiah 50:44; Zechariah 11:3). What will the prophet do when he has to tread the tangled maze of a jungle with the lions roaring round him?
Jeremiah 12:6
Called a multitude - Rather, “called aloud.” Compare Jeremiah 4:5. In all this Jeremiah was the type of Christ (compare Zechariah 13:6; Mark 3:21; John 7:5).