Jeremiah 18:8

If that nation against whom I have pronounced
Such a sentence as this, should immediately, upon the above declaration, do as Nineveh did: turn from their evil;
their evil of sin, their evil ways and works, as an evidence of the truth of their repentance for former sins: I will repent of the evil that one thought to do unto them;
as they change their course of life, God will change the dispensations of his providence towards them, and not bring upon them the evil of punishment he threatened them with; in which sense repentance can only be understood of God, he doing that which is similar to what men do when they repent of anything; they stop their proceedings, and change their outward conduct; so God proceeds not to do what he threatened to do, and changes his outward behaviour to men; he wills a change, and makes one in his methods of acting, but never changes his will.