Confession is easy when the sky is falling on you.
"Intercede before the Lord," Pharaoh pleads to Moses, "that with Him it may be enough, and there may be no more maledictory thunders nor hail from the presence of the Lord; and I will release you, and no longer hinder" (Targum Pseudo-Jonathan on Exodus 9:28).
The Targum's Aramaic, preserved in the paraphrase long associated with Yonatan ben Uzziel, is careful with its vocabulary. Pharaoh asks for the ra'amei la'ta to cease — the "maledictory thunders." The thunders of the curse. The Targumist is hinting that this is not mere weather. The thunderclaps carry a verdict. Each rumble is an indictment, and Pharaoh wants the indictment stopped before the palace collapses.
And then the promise: I will release you, and no longer hinder. A vow, spoken in the presence of a prophet. In the ancient Near East, a royal vow under witness was binding.
The Maggid teaches: Pharaoh's promise was sincere for as long as the thunder lasted. The moment the weather cleared, he would discover that his heart had not actually moved — only his fear. This is the pattern of false teshuvah: repentance that lasts only as long as the pain does. The true test is what happens after the sky is quiet again.