The words "I have sinned" occur nine times in the Bible, and of the nine we may except two. In the seventh chapter of Micah they are the language not of an individual, but of a Church. And the prodigal's use of them is, of course, not matter of fact or history, but only part of a parable. Of the seven that are left, four are utterly hollow and worthless; in God's scale, wanting, unreal, and unprofitable. One of these was Pharaoh's.
I. At what time God's hardening of Pharaoh's heart began, it is impossible exactly to determine. But, from the first, it was judicial. It is a common story. A sin is indulged till the man is given over to his sin, then the sin is made its own punishment. It was no doubt in consequence of this hardness that Pharaoh's repentance was never anything more than one after a worldly sort. If we allow ourselves to go through hardening processes we shall ultimately put repentance out of our power.
II. Pharaoh's "I have sinned" was (1) A mere hasty impulse. There was no thought in it; no careful dealing with his own soul; no depth. (2) The moving principle was fear. He was agitated: only agitated. Fear is a sign of penitence, but it is doubtful whether there was ever a real repentance that was promoted by fear only. (3) Pharaoh's thoughts were directed too much to man. He never went straight to God, and hence his confession was not thorough.
III. God accepts even the germs of repentance. Even Pharaoh's miserable acknowledgment had its reward. Twice, upon his confession, God stayed His hand. The loving Father welcomed even the approximation to a grace.
J. Vaughan, Sermons,7th series, p. 71.