Likutei Moharan 27:6/ליקוטי מוהר"ן כ״ז:ו׳

16. But it is only possible to attain a majestic countenance by rectification of the brit. This is as in (1 Chronicles 16:27), “Splendor and majesty are on His countenance,” when “oz (might) and gladness are in His place.” < OZ is> the brit, which is called boAZ ; and it is the gladness of the Matron. { “God is my might and song / He has become my deliverance / This is my Lord and I will glorify Him” (Exodus 15:2). }

2This is the meaning of, <“God is my might and song / He has become my deliverance.”> “My might” alludes to the brit ; “and song” is the concept of voice; “He has become my deliverance” corresponds to “He saw their affliction….”

3This is what our Sages taught: When the Jews ascended from the Sea, they raised their eyes to offer songs of praise (Sotah 30b). This is because at the Sea, the aspect of the brit was revealed. As our Sages said (Bereishit Rabbah 87:8): “The Sea saw and fled” (Psalms 114:3)—<saw> “and fled and went outside” (Genesis 39:12).

4“They raised their eyes.” This corresponds to a majestic countenance, the concept of “an elder is one who has acquired wisdom.” As Rashi explains: “Then the eyes of both of them were opened” (Genesis 3:7) —this was said regarding wisdom. “To offer songs of praise” corresponds to the voice, which is revealed through wisdom.

5And this is what [the Sages] taught: The babes and sucklings said, “Zeh (this) is my Lord and I will glorify Him” (Sotah 30b). “Zeh” alludes to the brit, as in (Exodus 3:12), “and zeh will be your sign.” “And I will glorify Him,” this corresponds to a majestic countenance.

6This is also the explanation of (Proverbs 29:3), “He who keeps company with harlots wastes his wealth.” <This is the loss of the voice.> As our Sages taught: “Honor God with your wealth” (ibid. 3:9) —do not read this “with honkha (your wealth),” but “with gronkha (your voice)” (Pesikta Rabbati #25). Thus by blemishing the brit, one’s voice becomes blemished.

7But Yaakov, who safeguarded his brit —as <is written> (Genesis 49:3), “the first of my manhood”—merited a voice. This is as in (ibid. 27:22), “The voice is the voice of Yaakov.”

8And with the concept of voice one merits peace, as in (Song of Songs 1:1), “The song of songs of ShLoMo”—to the King to whom ShaLoM (peace) belongs (Shir HaShirim Rabbah 1:11).

9Because of this, immediately after the voice of rinah associated with the Song of the Sea, the [Jewish people] merited the Sabbath of Peace. As is written (Exodus 15:23), “Then they came to Marah,” and Sabbath was instituted in Marah (Sanhedrin 56b).

10This is (Exodus 15:21), Vataan Lahem Miriam Shiru L’Hashem (“Miriam led them in song, ‘Sing to God’”), the first letters of which form the word ShaLOM. <In other words,> through <the voice> they merited peace.