Reb Pesach Malastovker was of the younger chasidim of the Alter Rebbe and a great chossid of the Mitteler Rebbe and Tzemach Tzedek. He was a brilliant gaon and had an immensely deep understanding in Chasidus. Reb Pesach was a great oived and a remarkable baal midos tovos.
Some enemies of Reb Pesach became jealous of his exceptional davening, and used forces of impurity to cast bad thoughts into his mind. Reb Pesach couldn't understand how such lowly thoughts were coming to him, and he brought his dilemma before the Alter Rebbe.
Recognizing the cause of the thoughts, the Rebbe took an apple and stared at it for a while. He then handed it to Reb Pesach and told him, "Say that you don't want the apple." Reb Pesach understood that the Rebbe wanted him to despise the apple and so he told the Rebbe, "How can I say that, when in truth I do desire it?"
The Alter Rebbe took the apple back and stared at it again. He then asked Reb Pesach a second time to state his dislike for the apple, but Reb Pesach insisted that he still desired it. The Alter Rebbe took the apple a third time, and this time Reb Pesach said with confidence, "Now I truly don't desire it."
The Alter Rebbe instructed Reb Pesach to eat the apple, and he was healed from his negative thoughts.
(למען ידעו ע' 270)
Reb Pesach would relate: "Each year I collect all of the questions I have in Chassidus in order to present them to the Rebbe when I enter yechidus. Yet, every time, as I enter the Rebbe's room all of my questions are resolved."
Reb Groinem, the mashpia in Lubavitch, would explain why this happened: Lack of clarity in Torah is brought about by klipa hiding the truth. When Reb Pesach entered the Rebbe's room where Elokus is revealed, his neshama felt the kedusha. As a result, the klipos were shattered and all of the questions disappeared.
(למען ידעו ע' 269)
