Siman 442

(6.) To one of the greatest of his close followers [Rabbi Shmuel Aizik] of blessed memory — he commanded him in the years of the close follower's youth — that during hisbodidus he should speak at great length specifically with each and every limb of his body — and explain to them that all bodily desires are vanity. For after all, every person's end is to die — and the body will be brought to the grave and all the limbs will decay and rot etc. — and similar kinds of words. And he conducted himself this way for some time. And afterwards he spoke with Rabbainu z"l and justified himself... Rabbainu o.b.m. said to him: "Strengthen yourself in this matter, and do not slacken your hand from it, and you will see afterward what will come of these utterances." And he heeded his counsel and fulfilled his words, until he merited afterward that each and every limb he spoke with in particular was drawn after his words so greatly, until the vitality actually went out of it and it remained without strength and without sensation at all. And he saw this plainly in the external limbs — such as the fingers of his hands and feet, and the like — until, with the inner limbs upon which the vitality depends, such as the heart and the like, he needed to curtail his words greatly, so that the vitality would not actually leave him, Merciful One save us. And I heard that once the aforementioned man spoke with those close to him about how this world is nothing, and what is the end of all the matters of the body, etc., as mentioned — and in the midst of his words he fainted and began to expire (in the Ashkenaz language: he was left weakened), and with great exertions, until his vitality returned and he was revived. And he said then that he merited, through the holiness of Rabbainu o.b.m., to such a level that at any time when he well recalls himself — from fear of punishment, and of the end and the finality of all the matters of this world — then all his limbs feel, even the little toe of his foot, as if he were already lying in the grave and decaying, etc. — until great strengthening is needed to hold his vitality within him, lest his soul actually depart, Merciful One save us: