During that long period of time, the king of Egypt died, and the Children of Israel sighed from the servitude, and they cried out, and their outcry from the servitude rose to Hashem.
The Ohr Hachaim deduces from the words at the end of the possuk that they did not cry out to Hashem and they did not daven to Him. All that they did was cry out in pain and suffering. Hashem heard this cry and accepted it as a reason to ameliorate the decree and redeem His nation.
Another explanation offered by the Ohr Hachaim is based on the possuk in Tehillim. Dovid Hamelech writes מִּן הַמֵצַר קָׂרָׂאתִּי יָׂ -הּ עָׂנָׂנִּי בַמֶרְ חָׂב יָׂ -הּ – Out of my straits I called upon Hashem. He answered me with great enlargement.
When Klal Yisroel davened to Hashem, they did so from their terrible pain and suffering. This is why Hashem listened to their cries. The Torah tells us that their cry arose to Hashem, because it was מִּן הָׂעֲבֹדָׂה- from the difficult work.
The Ohr Hachaim explains the difference in language used by the possuk with this. The Torah says וּקָעְז יַו – and they cried out. The Torah then says וַתַעַל שַוְעָׂתָׂם – and their begging arose. Why does the Torah change expressions from זעקה to שועה?
The Ohr Hachaim explains that they cried out in pain. When a person cries out in pain, his Tefillos are accepted on High. The outcry was a reason for the Tefillos to be accepted.
He adds another reason for the Torah’s addition of the words מִּן הָׂעֲבֹדָׂה. The Torah is telling us that the Tefillos arose directly from their work, without resorting to any Mal’achim or intermediaries. Some Tefillos require Mal’achim to bring them before Hashem. These did not.
