The preceding Pasuk (9:33) implies that the thunderous sounds ceased before the hail and rain. Why does our Pasuk list them in reverse order - that "Pharaoh saw that the rain, hail and sounds ceased"?
Riva: When Pharaoh saw rain with the hail, he saw that Hashem has mercy even when He is angry; so he said "Hashem ha'Tzadik" (9:27). Pharaoh asked only for the thunderous sounds and hail to cease. 1
Malbim: Really, first the sounds ceased to be produced above, but what was produced above was heard moments later on the ground. The hail and rain ceased after the sounds, but what was falling did not reach the ground, so it seemed that they ceased first. This gave room for Pharaoh to err 2 and say that it was not like Moshe said.
Riva: But not for the rain, which he was pleased with - but to no avail. Even Moshe was surprised that also the rain ceased, and Hashem told him that it was to induce Pharaoh to harden his heart, in order to send him more plagues.
Alshich: Pharaoh assumed that once Moshe prayed, there would be no new hail, but any hail already in the air would fall, or melt and fall as rain. He saw that the moment Moshe lifted his hands, no hail or rain fell. He concluded that it already stopped even before Moshe prayed. (Even though it says that Moshe left Pharaoh and the city to Daven (9:33), perhaps Pharaoh sent a Shali'ach to see if it stopped right after he Davened - PF.)
In the warning about the Makah of Barad, and the discussion of prayer to remove it, there was no mention of rain. Why does the Torah add here, that "the rain did not reach the ground"?
Midrash Sechel Tov: [Even] rain that comes from melting hail did not reach the ground. 1
Ba'al ha'Turim: To teach us that the Tefilah of Tzadikim withholds rain, and [we learn from David ha'Melech that it] also brings rain.
Oznayim la'Torah: Hashem stopped the rain from falling - even though neither did Pharaoh ask for this, nor did Moshe Daven for it to stop. This was in order to trick Pharaoh into believing that it was not the work of Hashem, thereby causing him to harden his heart and change his mind about sending Yisrael out. 2
Perhaps this was so Pharaoh could not point at a drop of rain and say 'it was a tiny hailstone that later melted!" Similarly, Moshe said 'about midnight' to thwart any claim that the plague was not like Moshe said. This is unlike the Malbim (refer to 9:34:151:2). Even if before, Hashem gave Pharaoh room to err (the magicians were able to imitate the first two plagues; also refer to 9:7:151:1), perhaps this was only while Pharaoh had free choice, but not once Hashem hardened his heart, starting with the plague of boils. (PF).
Oznayim la'Torah: As the Pasuk writes in Mishlei, "Im la'Leitzim Hu Yalitz ..." (Mishlei 3:34).
How did seeing that "the rain, hail and thunder had ceased," cause Pharaoh to harden his heart?
Gur Aryeh (to 7:3): The cessation of this Makah was fundamentally different than that of the other Makos. See above, 9:30:1.1:1.
Maharal (Gevuros Hashem Ch. 33, p. 125): Pharaoh was primarily afraid of the terrible thunder which accompanied the hail (see 9:28). 1 Therefore, once the thunder ceased, he felt as if the Makah never was. Also refer to 9:14:1.1:1***.
It was due to the change in the order in which they ceased; or the fact that the rain also ceased without Moshe having prayed for this. Refer to 9:34:151, and 9:34:152.
According to the Midrash, the same was true of the croaking in Makas Tzefarde'a; refer to 8:11:1.1:1.
Here it is implied that Pharaoh hardened his heart himself. Why, in 10:1, does Hashem say "I hardened his heart"?
Moshav Zekenim: The latter Pasuk teaches us that really, Hashem hardened his heart. Pharaoh hardened his own heart only after the first five plagues.
Riva: Hashem stopped the rain in order to help Pharaoh harden his heart. 1
Gur Aryeh: At first, Pharaoh hardened his own heart (9:34-35). Then, Hashem also hardened it further (10:1). Refer to 9:35:1:1.
Refer to 9:34:151:1 and its note.
Why does the Torah write specifically here that Pharaoh continued to sin?
Moshav Zekenim #1: Because Pharaoh saw that they needed rain and it did not fall to the ground. He increased to sin due to his frustration.
Moshav Zekenim #2: Because Moshe had not said that the rain will cease, therefore Pharaoh concluded that he was a liar.
Rashbam: Because after having admitted "va'Ani v'Ami ha'Resha'im" (9:27), and then continuing to detain Yisrael, the Torah considers him a Meizid.
