Tehillim, 114, 1-3: “In Yisrael’s leaving of Egypt, the house of Yaakov from a people of foreign tongue; Yehuda sanctified Him, Yisrael His ruler. The sea saw and escaped…”
Rashi, Tehillim, 114:2, Dh: Haysa Yehuda: “…This verse is homiletically explained in Agadda, ‘Yehuda sanctified Him’, in that Nachshon jumped into the sea and said ‘I will go in first’…”
Bereishis Rabbah, 87:8: Dh: And he went outside: “Rebbe Shimon Ish Katron says, ‘in the merit of Yosef’s bones, the sea split for Yisrael, as it says, ‘The sea saw and fled’ – in the merit of, ‘and he left his clothing in her hand and escaped.”
David HaMelech in Tehillim alludes to the events of Krias Yam Saf – he refers to Yehuda sanctifying HaShem, and then exclaims that the sea saw and then split – it does not tell us what exactly the sea saw. The Midrash teaches that what the sea ‘saw’ was the Aron that contained the body of Yosef Hatzaddik that the Jewish people brought with them out of Mitzrayim. The Midrash explains that in the merit of Yosef’s action of fleeing from Potiphar’s wife, the sea in turn ‘fled’ and split. Accordingly, it seems that the splitting of the sea was in Yosef’s merit. However, the Gemara cited by Rashi, when discussing the first part of the same verse in Tehillim, says that Yehuda’s sanctification refers to when Nachson Ben Amminadav of Yehuda was the first person to walk into the raging sea until the water reached up to his nose, and then split, seemingly in his merit. The obvious problem here is that based on Chazal’s drashos, it seems like the very same verse is alluding to totally separate reasons for the splitting of the sea – how do we understand this? It appears that both deeds were necessary to cause the sea to split, but why is this?
The first stage in approaching this question is to explain why davke these two actions merited the miracle of the splitting of the sea. With regard to Yosef, one possible approach is that, when faced with the nisayon with Potiphar’s wife, Yosef rose above his nature by resisting his natural human desires in a super-natural way and ran out of the room. In this merit, the sea went against its nature and ‘fled’ from itself so to speak, by splitting. A similar approach can be applied to Nachson Ben Amminadav – he went against the natural way of acting by walking straight into a raging sea until it reached the point where he could no longer breath. So again, by rising above the natural mode of behavior, he merited that the sea act in an ‘unnatural’ manner and split.
However, the question remains as to why both deeds seem to have been required? In order to answer this question, it is instructive to delve a little deeper into the unique roles of Yosef and Yehuda and this will enable to help us understand the significant of each of their actions that merited Krias Yam Suf. David HaMelech in Tehillim enumerates two kinds of avodas Hashem: “Sur meirah v’aseh tov” ; “leave evil and do good”. On an individual level, ‘leaving evil’ refers to avoiding sinning and overcoming one’s negative traits, whilst on a more public level it refers to fighting evil in the world. ‘Doing good’ refers to performing positive actions and developing one’s positive traits, whilst on a more public level it refers to bringing about increased avodas HaShem in the world.
The Shem Mishmuel explains that Yosef was the bechina of ‘sur merah’. He guarded himself from Arayos, refusing to even look at the Egyptian women who came to see him, and most significantly, when he overcame the test of Potiphar’s wife. He also acted to remove evil from others, by forcing the Egyptians to remove their Orlah through Bris mila, and in that way removing some of the yetser hara of arayos. Yehuda on the other hand, represents the bechina of ‘aseh tov’; He did positive actions, such as when he took responsibility for his action with Tamar, and he was sent to Mitzrayim to set up study halls to pave the way for the Jewish nation in a spiritual fashion.
In a similar vein, we know that that two Moshiachs will redeem the Jewish nation, one from Yosef and one from Yehuda – they will be known as Moshiach ben Yosef and Moshiach ben David – David himself was a descendant of Yehuda. The Shem Mishmuel writes that Moshiach ben Yosef will achieve the ‘sur merah’ aspect by defeating the enemies of the nation. In that way, he will pave the way for Moshiach ben David to complete the ‘aseh tov’ by bringing about the ingathering of the exiles and rebuilding the Beis HaMikdash.
Based on this understanding, it seems that two aspects of breaking nature were necessary to invoke enough merit to cause the sea to go against its nature – breaking nature in the realm of sur merah and breaking nature in the realm of aseh tov: Yosef broke nature through sur merah when he overcame his natural desires and ran away from Potiphar’s wife. Yehuda broke nature through aseh tov when he overcame his natural desire to remain safely on dry land, and walked up to his nose, in the raging waters.
The two acts of ‘supernatural’ strength combined to provide enough merit for the sea to act in a supernatural fashion and split. We also know that based on the concept of Maaseh Avos Simun L’Banim, the great actions of Yosef and Yehuda continue to have a positive effect on us – Yosef gave us the power to resist our yetser hara in difficult challenges, and Yehuda in taking responsibility and acting boldly even when it seems futile. May each of us merit, on our own level, to emulate Yosef and Yehuda in sur merah and aseh tov.
 Sotah, 37.
 Tehillim, 34:15.
 Shem MiShmuel, Vayigash, 5675.
 Shem MiShmuel Vayeishev; 5677.
 It could be added that the sea itself manifested ‘behavior’ reminiscent of both sur merah and aseh tov – aseh tov in allowing the Jewish people to go through, and sur merah in closing on the Egyptians and thereby destroying evil.