Likutei Moharan 11:6/ליקוטי מוהר"ן י״א:ו׳

16. This also corresponds to Halakhah (the law) and Kabbalah (the mystical tradition). As we find in the Kavanot (Shulchan Arukh HaAri, Shacharit shel Shabbat 4): Kabbalah is an aspect of Hishtachavu L’hashem B’ hadrat Kodesh (“Bow down to God in the grandeur of holiness”) (Psalms 29:2), the initial letters of which spell KaBbaLaH. Halakhah is an aspect of Hareeu L’hashem Kol Haaretz (“Sound a joyful note to God, all the earth”) (Psalms 100:1), the initial letters of which spell HaLaKhaH.

2Hishtachavu l’Hashem b’hadrat kodesh corresponds to the upper unification/marital relations of Shabbat. This is the upper brit, which contains the primary [expression] of bowing down, as in (Genesis 42:6), “Yosef’s brothers came and bowed themselves before him.” [Yosef] himself is “the grandeur of holiness,” as in (Deuteronomy 33:17), “His grandeur is like a firstborn ox.”

3Hareeu l’Hashem kol haaretz corresponds to the lower unification/marital relations of the weekdays. This is Metat whose rule is the six days of the week/the six orders of the Mishnah. This is hareeu {which connotes sounding a note and song}, as in (Isaiah 24:16), “From the k’naf (distant corner) of the earth we heard songs.” For Metat corresponds to KaNaF, similar to (Isaiah 30:2), “Your teacher will not yeKaNeF (distance himself) anymore.” This is because the Holy One clothes Himself in him during the six days of the week, as is known.