ת"ר סומא ומי שאינו יכול לכוין את הרוחות יכוין לבו כנגד אביו שבשמים שנא' (מלכים א ח, לה) והתפללו אל ה'
The Sages taught in a Tosefta: A blind person and one who is unable to approximate the directions and, therefore, is unable to face Jerusalem in order to pray, may focus his heart towards his Father in Heaven, as it is stated: “And they shall pray to the Lord” (I Kings 8:44).
Prayer without kavanah is like a body without a soul.
(Bahya Ibn Pakudah, 11th Century)
A somewhat different type of mystical “intentions” is found in the very popular manual of devotion called Yesod Ve-Shoresh Ha-Avodah (The Foundation and Root of Divine Worship) by Alexander Süsskind of Grodno (d. 1793). Alexander’s “intentions” are directed to the deeper meaning of the prayers in which the liturgy is used, in Alexander’s words, “to enflame the heart in the service of God.”
(א) אֲדנָי שפָתַי תִּפְתָּח וּפִי יַגִּיד תְּהִלָּתֶךָ:
(1) O Lord, open my lips and my mouth will declare Your praise.