Likutei Moharan, Part II 2:5/ליקוטי מוהר"ן·תנינא ב׳:ה׳

15. Now, perfected speech is the concept of the Holy Tongue. All the languages of the nations are lacking. They are imperfect and are called “the tongue of stammerers” (Isaiah 32:4). Perfection applies only to the Holy Tongue.

2And the Holy Tongue is linked to Shabbat, as in “nor speak of [weekday] matters” (Isaiah 58:13)—[that is,] your conversations on Shabbat should not resemble your weekday conversations (Shabbat 113b). This is as in “Thus shall you bless” (Numbers 6:23)—with the Holy Tongue (Sotah 38a). The Holy Tongue encompasses blessing and sanctity, for it is linked to Shabbat, which is called blessed and holy, as it is written (Genesis 2:3), “[God] blessed [the seventh day] and sanctified it.” And therefore, because the Holy Tongue is linked to Shabbat through perfected speech, which is the Holy Tongue, we draw the joy of Shabbat into the six weekdays.

3The weekdays are the concept of gloominess. Even the mitzvot we perform during the weekdays have the quality of heaviness. This is because the weekdays are ruled by Metat (Tikkuney Zohar #18, p.34a), who, as “servant,” signifies gloominess.

4But Shabbat is “son,” and there is rest then for those above and those below. Joy is awakened, and as a result all the mitzvot of the six weekdays are lifted up and raised out of the ATZVut (gloominess and heaviness). They are filled with meNuChah (rest) and joy, as in “and he begot a son. He named him NoaCh, saying: ‘This one will bring us relief from our work and from the ITZVon (toil) of our hands’” (Genesis 5:28-29). This refers to Shabbat, which is the concept of son and NoaCh— NaiCha (rest) for those above and those below (see Tikkuney Zohar #70, p.131a; Zohar I, 58b). He relieves and cheers all from [their] gloominess, as in “This one will bring us relief….”

5And when a person merits the Holy Tongue, which is linked to Shabbat, he causes the sanctity and joy of Shabbat to be drawn into the six weekdays. This is because the Holy Tongue is linked to Shabbat, and so Shabbat joy is channeled into the six weekdays through him. Thus “EL ELoHIM YHVH DiBeR (spoke)” {together with the number of words} has the same numerical value as SiMChaH (joy). For the perfection of speech, which is the Holy Tongue, brings joy.