Hassidout sur Les Psaumes 130:2

7 It is also possible to say:”on the full moon”(Psalms 81:4) and so on, as it is by the shofar that the sound is covered and the breath enters in stillness and the voice exits; and the sound hints at elevation from low to high for the foot/bottom part of the Kuf (the word sound/kol consists of a kuf and a vav and a lamed) has the lowest point of all the (Hebrew) letters and the Yud that makes up the very top of the letter Lamed is the highest of the all. The letter Vav that is between them teaches על שית עזקאין דקנה from the Zohar that everything devolves from it. And with the help of the sound elevation occurs from the lowest to the highest level and this is the meaning of the verse: “Out of the depths I call You, O LORD. O Lord, listen to my cry” (Psalms 130:2-3) and a person needs to: “to walk modestly with your G-d” (Micha 6:8) and this narrative is hinted at with the sound of the shofar that the voice is inserted into the instrument in a whisper, invisibly, and afterwards the sound emerges audibly and is revealed. So does the person have to act: in the beginning s/he needs to hide the actions until they are openly recognizable by themselves, and this is the meaning of: “Blow the horn on the new moon” (Psalms 81:4) to renew/newly reveal (the word chodesh/moon and the word chadash/new are spelled identically; translator) his/her deeds. This is as regards “the voice of the shofar” and ”on the full moon”, as has been cited above.