Hebrew, then English. Open "What it means" under any line for the explanation.
The siddur's note: this is said in memory of leaving Egypt. Say it with joy, as if you were the one saved at the sea.
וַיּוֹשַׁע יְיָ בַּיּוֹם הַהוּא אֶת יִשְׂרָאֵל מִיַּד מִצְרָיִם וַיַּרְא יִשְׂרָאֵל אֶת מִצְרַיִם מֵת עַל שְׂפַת הַיָּם.
Hashem saved on that day Israel from the hand of Egypt. Israel saw the Egyptians dead on the shore of the sea.
What it means
On that day Hashem saved Israel from the hand of Egypt, and Israel saw the Egyptians dead on the shore of the sea.
וַיַּרְא יִשְׂרָאֵל אֶת הַיָּד הַגְּדֹלָה אֲשֶׁר עָשָׂה יְיָ בְּמִצְרַיִם וַיִּירְאוּ הָעָם אֶת יְיָ וַיַּאֲמִינוּ בַּייָ וּבְמשֶׁה עַבְדּוֹ.
Israel saw the great hand that Hashem used against Egypt. The people feared Hashem, and they believed in Hashem and in Moshe His servant.
What it means
Why add "and in Moshe"? If they believed Moshe, surely they believed God. The Mekhilta (an early midrash on the book of Shemot) answers: to teach that trusting the shepherd of Israel, the leader God sent, is like trusting the One who spoke and the world came to be.
Mekhilta DeRabbi Yishmael, Beshalach 7The song:
אָז יָשִׁיר משֶׁה וּבְנֵי יִשְׂרָאֵל אֶת הַשִּׁירָה הַזֹּאת לַייָ וַיֹּאמְרוּ לֵאמֹר אָשִׁירָה לַייָ כִּי גָאֹה גָּאָה סוּס וְרֹכְבוֹ רָמָה בַיָּם.
Then sang Moshe and the children of Israel this song to Hashem. They said: I will sing to Hashem, for He is high above all. Horse and rider He threw into the sea.
What it means
Then Moshe and the children of Israel sang this song to Hashem. They said: I will sing to Hashem, for He is high above all. Horse and rider He threw into the sea.
Az yashir is "then he will sing," not "sang." Rashi (the classic commentator on the Torah, France, died 1105) gives the plain reading: when Moshe saw the miracle, his heart told him to sing, and he did.
Rashi on Shemot 15:1עָזִּי וְזִמְרָת יָהּ וַיְהִי לִי לִישׁוּעָה זֶה אֵלִי וְאַנְוֵהוּ אֱלֹהֵי אָבִי וַאֲרֹמְמֶנְהוּ.
God is my strength and my song, and He became my rescue. This is my God, and I will make Him beautiful; the God of my father, and I will raise Him high.
What it means
"This is my God" sounds like pointing. Rashi says that is what happened: God showed Himself in His glory, and they pointed at Him with a finger.
Rashi on Shemot 15:2יְיָ אִישׁ מִלְחָמָה יְיָ שְׁמוֹ.
Hashem is a man of war; Hashem is His name.
What it means
Hashem is a warrior; Hashem is His name.
מַרְכְּבֹת פַּרְעֹה וְחֵילוֹ יָרָה בַיָּם וּמִבְחַר שָׁלִשָׁיו טֻבְּעוּ בְיַם סוּף.
Pharaoh's chariots and his army He cast into the sea; his best officers sank in the Sea of Reeds.
What it means
Rashi says tube'u, "sank," is the word for sinking into mud. The sea turned to mud. It was payback in kind: the Egyptians had worked Israel with mortar and bricks.
Rashi on Shemot 15:4תְּהֹמֹת יְכַסְיֻמוּ יָרְדוּ בִמְצוֹלֹת כְּמוֹ אָבֶן.
The deep waters covered them; they went down into the depths like a stone.
יְמִינְךָ יְיָ נֶאְדָּרִי בַּכֹּחַ יְמִינְךָ יְיָ תִּרְעַץ אוֹיֵב.
Your right hand, Hashem, glorious in strength, Your right hand, Hashem, shatters the enemy.
What it means
Your right hand, Hashem, is glorious in strength; Your right hand, Hashem, shatters the enemy.
Why "Your right hand" twice? Rashi's own reading: it is the same right hand. It saves Israel and smashes the enemy at the same time, two jobs with one hand, which no person can do.
Rashi on Shemot 15:6וּבְרֹב גְּאוֹנְךָ תַּהֲרֹס קָמֶיךָ תְּשַׁלַּח חֲרֹנְךָ יֹאכְלֵמוֹ כַּקַּשׁ.
In Your great majesty You tear down Your opponents; You send out Your fury, it eats them up like straw.
What it means
In Your great majesty You tear down those who rise against You; You send out Your fury, and it eats them up like straw.
Who are "those who rise against You"? Rashi: the ones who rise against Israel. Whoever plots against God's people is called God's enemy.
Rashi on Shemot 15:7וּבְרוּחַ אַפֶּיךָ נֶעֶרְמוּ מַיִם נִצְּבוּ כְמוֹ נֵד נֹזְלִים קָפְאוּ תְהֹמֹת בְּלֶב יָם.
With the breath of Your nostrils the waters piled up. The flowing waters stood up like a wall. The depths froze in the heart of the sea.
What it means
Does God have nostrils? Rashi: the Torah speaks about God the way it would about a human king, so that people can understand. When a person is angry, breath comes out of the nose.
Rashi on Shemot 15:8אָמַר אוֹיֵב אֶרְדֹּף אַשִּׂיג אֲחַלֵּק שָׁלָל תִּמְלָאֵמוֹ נַפְשִׁי אָרִיק חַרְבִּי תּוֹרִישֵׁמוֹ יָדִי.
The enemy said: I will chase, I will catch up, I will split the loot; I will have my fill of them; I will draw my sword; my hand will wipe them out.
What it means
Rashi: Pharaoh said this to his own people, to talk them into the chase. I will chase, I will catch up, I will split the loot with my officers and my servants.
Rashi on Shemot 15:9נָשַׁפְתָּ בְרוּחֲךָ כִּסָּמוֹ יָם צָלֲלוּ כַּעוֹפֶרֶת בְּמַיִם אַדִּירִים.
You blew with Your wind; the sea covered them. They sank like lead in the water, the mighty ones.
What it means
You blew with Your wind; the sea covered them. The mighty ones sank like lead in the water.
Pause after bamayim, "in the water." The Mishnah Berurah (a guide to daily Jewish law, published 1884 to 1907) says adirim, "the mighty ones," means the Egyptians. It does not describe the water.
Mishnah Berurah 51:17מִי כָמֹכָה בָּאֵלִם יְיָ מִי כָּמֹכָה נֶאְדָּר בַּקֹּדֶשׁ נוֹרָא תְהִלֹּת עֹשֵׂה פֶלֶא.
Who is like You among the mighty, Hashem? Who is like You, glorious in holiness, awesome in praises, doing wonders?
What it means
Ba'elim, "among the mighty," has no yud here. Chizkuni (a French Torah commentary, 1200s) says this hints at ba'ilmim, "among the silent." The Mekhilta reads it so: who is like You, who sees Your children shamed and is silent? The Gemara (the rabbis' discussions on the Mishnah) reads it this way about Titus, the Roman general who mocked God in the Temple.
Mekhilta, Shirah 8; Gittin 56b; Chizkuni on Shemot 15:11נָטִיתָ יְמִינְךָ תִּבְלָעֵמוֹ אָרֶץ.
You stretched out Your right hand; the earth swallowed them.
What it means
Why does the earth swallow them, at sea? Rashi: from here we learn they were given a burial. It was a reward, because the Egyptians had once said "Hashem is in the right" (Pharaoh's words during the plague of hail, Shemot 9:27).
Rashi on Shemot 15:12; Shemot 9:27נָחִיתָ בְחַסְדְּךָ עַם זוּ גָּאָלְתָּ נֵהַלְתָּ בְעָזְּךָ אֶל נְוֵה קָדְשֶׁךָ.
You led with Your kindness the people You redeemed; You guided them with Your strength to Your holy home.
What it means
With Your kindness You led the people You redeemed; with Your strength You guided them to Your holy home.
Nachita, "You led," is past tense, though they had not reached that holy home yet. Ibn Ezra (Rabbi Avraham ibn Ezra, Spain, 1100s) says prophecy often uses the past in place of the future.
Ibn Ezra on Shemot 15:13שָׁמְעוּ עַמִּים יִרְגָּזוּן חִיל אָחַז ישְׁבֵי פְּלָשֶׁת.
Nations heard and shook; trembling gripped the people of Philistia.
What it means
Why would the Philistines shake? Rashi: they had killed men of the tribe of Efrayim who rushed out of Egypt early, by force, before the time God set. The book of Divrei HaYamim (Chronicles) records that the men of Gat killed them.
Rashi on Shemot 15:14; Divrei HaYamim I 7:21אָז נִבְהֲלוּ אַלּוּפֵי אֱדוֹם אֵילֵי מוֹאָב יֹאחֲזֵמוֹ רָעַד נָמֹגוּ כֹּל ישְׁבֵי כְנָעַן.
Then the chiefs of Edom panicked; trembling seized the mighty of Moav; all the people of Canaan melted away.
What it means
Then the chiefs of Edom panicked; trembling seized the mighty men of Moav; all the people of Canaan melted away.
Edom and Moav had nothing to fear: Israel was not coming for their land. Rashi says they shook anyway, out of grief, pained at the honor Israel was getting.
Rashi on Shemot 15:15תִּפֹּל עֲלֵיהֶם אֵימָתָה וָפַחַד בִּגְדֹל זְרוֹעֲךָ יִדְּמוּ כָּאָבֶן עַד יַעֲבֹר עַמְּךָ יְיָ עַד יַעֲבֹר עַם זוּ קָנִיתָ.
Dread and fear fall on them; at the greatness of Your arm they are still as stone, until Your people pass over, Hashem, until the people You acquired pass over.
What it means
Why "until they pass over" twice? Onkelos, the Aramaic translation, names two crossings: until Your people cross the Arnon river, until they cross the Jordan. Rashi follows him.
Onkelos and Rashi on Shemot 15:16תְּבִאֵמוֹ וְתִטָּעֵמוֹ בְּהַר נַחֲלָתְךָ מָכוֹן לְשִׁבְתְּךָ פָּעַלְתָּ יְיָ מִקְּדָשׁ אֲדֹנָי כּוֹנְנוּ יָדֶיךָ.
You will bring them and plant them on the mountain of Your inheritance, the place You made, Hashem, for You to dwell in, the Sanctuary, my Master, that Your hands set up.
What it means
Rashi: the Temple is beloved. The world was made with one hand, as the prophet Yeshayahu says, "My hand founded the earth." The Temple is made with two: "Your hands set up." When will it be built with both hands? When "Hashem will reign forever," the next line.
Rashi on Shemot 15:17Say this verse twice, then once in Aramaic.
יְיָ יִמְלֹךְ לְעֹלָם וָעֶד. יְיָ יִמְלֹךְ לְעֹלָם וָעֶד. יְיָ מַלְכוּתֵהּ קָאֵים לְעָלַם וּלְעָלְמֵי עָלְמַיָּא.
Hashem will reign forever and ever. Hashem will reign forever and ever. Hashem, His kingdom stands forever and for all time.
What it means
Why twice? The Abudarham (a classic commentary on the prayers, Spain, 1300s) says this verse is the end of the song, and without the repeat it would not look like the end. The Mishnah Berurah adds, in the name of the Arizal (the great Kabbalist of Tzfat, 1500s), to say it once more in Aramaic.
Abudarham, Songs of Praise; Mishnah Berurah 51:17כִּי בָא סוּס פַּרְעֹה בְּרִכְבּוֹ וּבְפָרָשָׁיו בַּיָּם וַיָּשֶׁב יְיָ עֲלֵהֶם אֶת מֵי הַיָּם וּבְנֵי יִשְׂרָאֵל הָלְכוּ בַיַּבָּשָׁה בְּתוֹךְ הַיָּם.
When Pharaoh's horses came with his chariots and riders into the sea, Hashem brought the sea's waters back over them, and the children of Israel walked on dry land through the sea.
What it means
When Pharaoh's horses came with his chariots and his riders into the sea, Hashem brought the waters of the sea back over them, and the children of Israel walked on dry land in the middle of the sea.
In the Torah this verse comes right after the song. Is it part of it? The Mishnah Berurah brings the view, in the Arizal's name, to say it, since it too belongs to the song. In the name of the Vilna Gaon (the great Torah scholar of Vilna, died 1797), some do not say it.
Mishnah Berurah 51:17Three verses from Tehillim and the Prophets close it:
כִּי לַייָ הַמְּלוּכָה וּמשֵׁל בַּגּוֹיִם.
For kingship is Hashem's, and He rules over the nations.
What it means
This is from Tehillim 22, the psalm that opens "My God, my God, why have You left me?" Near its end it sees the whole world turning to God. Radak (Rabbi David Kimchi, Provence, around 1200): then all the nations will know that the kingship is God's.
Tehillim 22:2, 22:28-29, with Radakוְעָלוּ מוֹשִׁעִים בְּהַר צִיּוֹן לִשְׁפֹּט אֶת הַר עֵשָׂו, וְהָיְתָה לַייָ הַמְּלוּכָה.
Rescuers will go up on Mount Zion to judge Mount Esav, and the kingship will be Hashem's.
What it means
The last verse of Ovadyah, a one-chapter book of prophecy about Edom, the nation descended from Esav. Radak says the "rescuers" are the Mashiach and those with him.
Ovadyah 1:1 and 1:21, with Radakוְהָיָה יְיָ לְמֶלֶךְ עַל כָּל הָאָרֶץ בַּיּוֹם הַהוּא יִהְיֶה יְיָ אֶחָד וּשְׁמוֹ אֶחָד.
Hashem will be King over all the earth. On that day Hashem will be One and His name One.
What it means
"On that day Hashem will be One." Isn't He One today? The Gemara answers: today, on good news we bless "who is good and does good," and on bad news "the true Judge." In the world to come, it will all be "who is good and does good."
Pesachim 50a