Siman 589

(146.) Once one of our people spoke with Rabbainu z"l about the matter that sometimes one feels that the words come from the nape of the neck and not from the heart [and something similar to this is explained in his words z"l in Sichos HaRan, 16]. Rabbainu z"l replied: "Do you know what the heart is and what the nape of the neck is?" [in Yiddish: "di vaist veliches es iz hartz oder in akin"].