Highest virtue, Speak in your vernacular, and Set a designated hour daily
It has already been explained, that hisbodidus is a great virtue, and a very correct and upright way to draw close through it to Hashem Yisburach. And it is necessary for everyone to set for this some hours of the day, to express one’s words (-sentiments) before Hashem Yisburach in the spoken language, like in these provinces, in Yiddish ("lushon Ashkenaz", today this can very readily refer to English vernacular), in which we speak. Because in the native tongue it is much easier to express well all one’s words, and all that is with (-upon) his heart he should converse before Hashem Yisburach with argumentations and exculpations, and words of appeasement and entreaty, that he should merit to draw close to Him Blessed He, everyone according to what he knows the maladies of his heart, and how distant he is from Hashem Yisburach. And the actual virtuous ascendances of this practice cannot be explained nor fathomed, because this practice exceeds everything, and it includes all the service of Hashem. Because through this one can come to all the goodness in this world and the next. Because everything can be accomplished through prayer and entreaty. And all the great tzadikim did not come to their levels except through this practice, and one who applies himself to understand the matter, will understand on his own the great ascendances of this practice. Fortunate is the one who merits to set for himself for this a designated hour every single day, and the rest of the day he should be joyous.
(Likutay Moharan II, Torah 25; Outpouring of the Soul, article 2)