Indeed, in the Midrash Pliah, the command 'And you shall remain silent' is interpreted to mean refraining from singing. This is puzzling, as they cried out in prayer, and what place does singing have in a time of distress? This issue is elaborated upon in the book Divrei Yoel. [We also find something similar explicitly stated in the Mekhilta (at the end of that section): "The Holy One said to Moses: Moses, My children are in distress, the sea is closing in, and the enemy is pursuing, and you are standing and prolonging your prayer. He said before Him: What can I do? He replied: 'And you, lift up your staff and stretch out your hand over the sea, etc.' (Exodus 14:16) – And you shall exalt and praise and sing and give thanks and greatness and splendor and praise to the One to whom wars belong."]

To explain the words of the Midrash, let's bring the continuation of its words there (Parasha 5): "He said before Him, Master of the Universe, what can I do? He replied, 'And you, lift up your staff.' And what did Moses and Israel say by the sea? 'The Lord will reign forever and ever' (Exodus 15:18)." It implies that they said this before the sea split.

This aligns precisely with the text we recite in prayer: "Moses and the children of Israel sang a song to You with great joy and all said, 'Who is like You among the gods, O Lord, etc.'" And then we say again: "A new song, the redeemed praised Your great name on the seashore, all together gave thanks and proclaimed and said, 'The Lord will reign forever and ever.'" At first glance, it appears that they already mentioned singing a song, so why is it repeated? Moreover, why is the verse 'The Lord will reign forever and ever' included in the second song and not in the first?

According to the words of the Midrash, it is resolved that they indeed sang twice – after the splitting of the Red Sea, they said: 'Who is like You among the gods, O Lord.' Before the splitting of the Red Sea, they said: 'The Lord will reign forever and ever.' Therefore, it is emphasized that they said it 'on the seashore,' meaning before the splitting of the Red Sea. It appears that even before they saw a way to escape their impending distress, they already gave thanks and proclaimed and sang.

Now the words of the Midrash Pliah, 'And you shall remain silent – from singing,' can be explained. According to our explanation, since they had already begun to give thanks, they likely wanted to continue thanking for all the miracles and wonders that God had performed for them until they left Egypt, and for the Exodus itself. Therefore, God said to them: And you shall remain silent from singing, for the time has come for the splitting of the Red Sea.