Then shall the prophet ... - Or, "shall be known as the prophet whom the Lord hath truly sent."

When the word of the prophet shall come to pass - Here is the criterion. He is a true prophet who specifies things that he says shall happen, and also fixes the time of the event; and the things do happen, and in that time.

You say that Nebuchadnezzar shall not overthrow this city; and that in two years from this time, not only the sacred vessels already taken away shall be restored, but also that Jeconiah and all the Jewish captives shall be restored, and the Babylonish yoke broken, see Jeremiah 28:2, Jeremiah 28:3, Jeremiah 28:4. Now I say that Nebuchadnezzar will come this year, and destroy this city, and lead away the rest of the people into captivity, and the rest of the sacred vessels; and that there will be no restoration of any kind till seventy years from this time.

The prophet which prophesieth of peace,.... Of prosperity, of good things, as Hananiah did, and which are always acceptable to men; and such a prophet is agreeable to them:

when the word of the Lord shall come to pass; when the prophecy of good things, which he delivers in the name of the Lord, shall be filled:

then shall the prophet be known that the Lord hath truly sent him; and not till then; it is the event that must make it manifest: in the other case it may be in a good measure known before it comes to pass, and, whether it comes to pass or not, that a prophet is a true prophet; because his prophecies are agreeable to the word and the declared will of God; contain evils threatened on account of sin, and in order to bring men to repentance, which must needs be right; and besides, they have no interest of their own to serve, but run contrary to the stream of the people, and are exposed to their rage and censure: whereas, a man that prophesies of peace, he is more to be suspected of flattering the people, and of prophesying out of his own heart; and nothing but the event can show him a true prophet; which if he delivers with a proviso, that the people do not do that which is evil in the sight of God, to provoke him to deny them the promised good, is always certainly fulfilled; and if it is not, then he appears manifestly a false prophet.

The prophet which prophesieth of peace, when the word of the prophet shall come to pass, then shall the prophet be known, that the LORD hath truly sent him.

9. peace-Hananiah had given no warning as to the need of conversion, but had foretold prosperity unconditionally. Jeremiah does not say that all are true prophets who foretell truths in any instance (which De 13:1, 2, disproves); but asserts only the converse, namely, that whoever, as Hananiah, predicts what the event does not confirm, is a false prophet. There are two tests of prophets: (1) The event, De 18:22. (2) The word of God, Isa 8:20.

28:1-9 Hananiah spoke a false prophecy. Here is not a word of good counsel urging the Jews to repent and return to God. He promises temporal mercies, in God's name, but makes no mention of the spiritual mercies which God always promised with earthly blessings. This was not the first time Jeremiah had prayed for the people, though he prophesied against them. He appeals to the event, to prove Hananiah's falsehood. The prophet who spake only of peace and prosperity, without adding that they must not by wilful sin stop God's favours, will be proved a false prophet. Those who do not declare the alarming as well as the encouraging parts of God's word, and call men to repentance, and faith, and holiness, tread in the steps of the false prophets. The gospel of Christ encourages men to do works meet for repentance, but gives no encouragement to continue in sin.