Consider what Jeremiah's business was, and how the potter might help him in understanding and performing it.
I. Jeremiah sees a man engaged in a task to which he is devoting all his thoughts. He designs to make some clay into a vessel of a certain shape; the form or pattern is present to his mind; he is fully resolved that the material with which he is working shall come forth in that form and no other. But apparently it disappoints him. One piece of clay after another is marred in his hands; he has to break his vessel again and again; he goes on perseveringly till he has done the thing which he intended to do. If there is any force or worth in the analogy at all, it must mean that there is a form according to which God is seeking to mould men and nations. It must imply that He is patiently, continually, working for the accomplishment of this purpose. Here, then, was the mystery of a people's repentance. If they acknowledged the will which was working upon them, if at any time they yielded to it and desired to be formed by it, this was that conversation and inward change which He was seeking to produce.
II. The prophet looks upon this symbol as teaching him the principle of God's government of a people. I apprehend that we shall learn some day that the call to individual repentance and the promise of individual reformation has been feeble at one time; productive of turbulent, violent, transitory effects at another; because it has not been part of a call to national repentance, because it has not been connected with a promise of national reformation. We must speak again the ancient language that God has made a covenant with the nation, and that all citizens are subjects of an unseen and righteous King, if we would have a hearty, inward repentance which will really bring us back to God.
III. Jeremiah could not bring the image of the potter's work to bear with its proper force upon Israelites at that moment if he confined the purpose of God within the limits which they had fixed for it As he gazed on the potter and saw how one piece of clay after another was marred, and yet how the thing he designed was at last done; it came with an awful vision of what was preparing for his land, with a bright vision of what must ultimately follow from every judgment. That which seemed now compact, and yet which consisted of elements that were always ready to separate from each other, might split into fragments: but the vessel must be made: not after some different type, but after the original and perfect type which dwelt not in the dead matter but in the living mind of Him who was shaping it.
F. D. Maurice, Prophets and Kings of the Old Testament,p. 395.
Reference: Jeremiah 18:1-10. E. H. Plumptre, Expositor,1st series, vol. iv., p. 469.