"If you are careful to heed my commandments, which I am commanding to you today, to love the Lord your G‑d, to serve Him with all your heart and with all your soul, then I will give the rains in their proper time..." (Deut. 11:13, the second paragraph of the Reading of the Shema prayer)

Rashi: "…to love the L-rd your G‑d, to serve Him with all your heart" is the service of the heart - prayer."

The Yismach Moshe, Rabbi Moshe Teitlebaum of Uhely, asks some penetrating questions. Why is prayer called "the service of the heart", and why is it more so than other types of "heartful" ways of service such as Love and Fear? Prayer must be uttered with the lips and heard by one's own ears, while the heart is associated with silent meditation. Isn't prayer really the service of the lips? The combination of the external service with internal intention is tefilla….

The answer is found in the root of the Hebrew word for "prayer" itself, "tefilla". "Tefilla" means "joining" or "connecting". (See Gen. 30:8, Rashi concerning the naming of Naftali.) Tefilla requires the mouth, not just the meditations of the heart. Service is not only the sweet singing of praises to G‑d. The physical act of voicing prayer helps a person to arouse his intentions. The combination of the external service with internal intention is tefilla. Together they make a person a receptacle for receiving the goodness of the Creator. This service then becomes an offering before G‑d - focused intention combined with the sweetness of the melody and the song of prayers.

The internal intentions of the heart and the external movement of the lips work together in another way to activate our prayer. Sometimes the words don't come out. Then the inner intentions can be used to stimulate the mouth to pronounce the prayers. On the other hand, there are times that the heart feels empty. The verbal expression of the prayer can arouse the heart to come alive. (This also explains why sometimes people shuckle [i.e. sway forward and back] when they pray; the physical motion pulls out the intentions of the heart, giving them expression as if they were words.)

The Yismach Moshe also explains that this idea represents a solution to a well known controversy between the Rambam and a later sage, the Tolaat Yaacov. The Rambam maintains that the primary duty of the Jew is to remember G‑d unceasingly and to believe in Him. The the Tolaat Yaacov disagrees with the Rambam, maintaining that the Jew must actively engage in mitzvot in order to uphold the world. The intentions and the meditations of the heart (remembering G‑d, faith) work mutually with the active verbal expressions of the mouth. (dynamic performance of mitzvot).

Tefilla truly is the Service of the Heart since it combines the mouth and the heart in unity of service to the Creator.

[Based on Yismach Moshe by Rabbi Moshe Teitlebaum of Uhely
First published http://www.nishmas.org/chassidus/devarim/re'eh5758.htm)