Adapted from: The Abuchatzeira Legacy Haggadah by Rabbi Mordechai Lebhar

At the splitting of the sea, Bnei Yisrael had more emunah (faith) than when in Egypt.

ויושע ה‘ ביום ההוא את־ישראל מיד מצרים וירא ישראל את מצרים מת על שפת הים: וירא ישראל את־היד הגדלה אשר עשה ה‘ במצרים וייראו העם את ה‘ ויאמינו בה‘ ובמשה עבדו, Hashem saved on that day… and Yisrael saw Egypt… and Yisrael saw the Great Hand… and the nation feared Hashem and had emunah (faith) in Hashem and Moshe His servant (Shemot 14:30-31).

This verse must be understood; did they only now have emunah? In Egypt they also had emunah, as the verse states (4:31): ויאמן העם, and the nation believed! Also, Chazal teach in the Mechilta (Beshalach Vayehi 6) that Bnei Yisrael were redeemed from Egypt only in the merit of emunah, as is stated ויאמן העם, so why is the verse telling us here that only after they saw the Egyptians drowning, and they saw the Great Hand of Hashem, did they have emunah in Hashem and His servant Moshe, implying that until that point they didn’t have emunah?

There are several levels in emunah. The first emunah is that of the brain. A higher emunah is that of the heart, bringing the emunah from its knowledge in the brain to the feeling of the heart, so that all one’s feelings are filled with emunah in Hashem, because the distance between the brain and the heart is as far as the distance between heaven and earth. However, the recognition of the brain and heart is not sufficient, as we sometimes see a person loses himself when something frightening happens and his emunah is not strong enough for him to retain peace of mind. Therefore, after he has merited to bring emunah to the depths of his heart, he will continue to bring emunah to his limbs, until emunah in Hashem is instilled in all his limbs and they should all feel that there is none other than Hashem, as is written (Tehillim 35:19): כל עצמותי תאמרנה ה’ מי כמוך, All my bones shall say, “Hashem, who is like You!” Only if he managed to root the faith in all his limbs will he be able to withstand fear and remain peaceful and safe at all times.

This is the meaning of ויאמינו בה’ ובמשה עבדו, they believed in Hashem and His servant Moshe, at Keriat Yam Suf. At first their emunah was fixed in the mind and did not spread to their actions, as Moshe Rabbeinu said (Shemot 4:1), והן לא יאמינו, they will not believe, because their emunah was not strong enough to control their whole body. But Hashem replied that His children are מאמינים בני מאמינים, believers, the children of believers, and little by little they were able to bring the emunah to their hearts and to their limbs, until Keriat Yam Suf, when the emunah spread in them completely and they were moser nefesh (sacrificed themselves) to enter the sea without fear. This is the meaning of ויאמינו בה’ ובמשה עבדו — they had complete emunah, reaching the highest level of emunah.

We could also say that their emunah did not suffice as they also needed total devotion of self (mesirut nefesh) to fulfill Hashem’s will. But when they heard from Moshe that they would see 

Hashem’s salvation, their mesirut nefesh was marred, because they didn’t truly sacrifice since they heard from Moshe that they would merit miracles! Therefore, Hashem told Moshe (Shemot 14:15), מה תצעק אלי, “Stop praying to Me”; the main yeshuah was to come from Yisrael’s mesirut nefesh without knowing that they would merit miracles. Therefore, the verse continues, דבר אל בני ישראל ויסעו, tell Bnei Yisrael to travel, without knowing how the yeshuah would come. Indeed, when they showed self-sacrifice (by continuing into the open waters) even without expecting a miracle, they merited Hashem’s yeshuah.

(Rav David Chai Abuchatzeira, Milta Chadeta, Beshalach, 5783)