פרשת מטות - מסעי תשט"ו - ערי מקלט

ונס שמה רוצח מכה נפש בשגגה, “and to such a city a murderer who killed a person unintentionally shall flee.” Such a person is not guilty of the death penalty seeing he did not intend to kill his victim. This law demonstrates that the heart of the person is the prime driving force of man’s activities. This principle applies to the performance of all the commandments as well as to the commission of any sins. Exile is the penalty decreed here seeing that the man’s heart was not associated with his action. The death penalty never applies unless body and heart had committed the sin in question in tandem, in agreement with each other. The body contributes the relevant movement, the heart the relevant intention. Seeing in the example mentioned there was no such co-ordination between body and mind, the guilty party only has to be exiled.
By the same token, if a person performed a commandment, in accordance with all its details but his heart was not involved, i.e. he did not mean to perform a commandment by doing what he did, he will not receive a reward for his deed (compare Nazir 23). This is what David meant when he said in Psalms 119,48: “I raise my palms toward Your commandments which I love, etc.” The “raising of hands” which David speaks of is the intention harboured by his heart. We find these two words side by side in Lamentations 3,41: “let us raise our hearts with our palms.”