(Excerpt from Chumash Mesoras Harav)
צוּר יְלָדְךָ תֶּשִׁי – You forgot the [Mighty] Rock Who bore you.
We are all included in God’s existence, and His consciousness encompasses all our separate existences. Maimonides devotes a chapter in his Guide for the Perplexed (1:16) to an examination of the term “rock”: It is a term denoting a hard stone, like flint…It is further a term denoting the quarry from which quarry-stones are hewn. Thus: “Look unto the rock whence you were hewn” (Is. 51:7). Subsequently, in derivation from this last meaning, the term was used to figuratively to designate the root and principle of everything. It is on account of this that after saying “Look unto the rock whence you were hewn,” Scripture continues: “Look unto Abraham your father” (Is. 51:1), giving…an interpretation according to which “the rock whence you were hewn” is “Abraham your father.” Tread therefore in his footsteps, adhere to his religion, and acquire his character, inasmuch as the nature of a quarry ought to be present in what is hewn from it. On account of this last meaning God…is designated as rock, as He is the principle and efficient cause of all things other than Himself.
Maimonides concludes the chapter by citing the verse where God says to Moses: Behold, there is a place with Me (Ex. 33:21). If you, Moses, exist, it is because I, God, share a place with you. God is the origin of the world, not in the sense of creating it long ago, but in the sense that the root is the origin of the tree. (Between Philosophy and Halakhah, pp. 194-195)
Rashi comments: Our Rabbis explained the word תֶּשִׁי homiletically to mean: When God comes to bestow good upon you, you provoke Him to anger and weaken [מַתִּישִׁין] His power to do good. When Israel sins, God is in a sense “helpless.” My instructor in cheder described how God cries in mourning for His Temple during the nine-day mourning period leading up to Tisha B’Av. I asked him, “I don’t understand. Why does God have to cry? He is omnipotent! With His word He created the entire world; certainly He can rebuild the Temple!”
As a child I did not comprehend my rebbe‘s answer. Many years later I understood that God cannot act alone, so to speak. There is no awakening above (is’arusa dil’eila) without a corresponding awakening below (is’arusa dil’tata). Man himself must reveal the Shechinah. Man can find God in every event, time, and place—from the morning sunrise through the evening sunset, in the seas and the growth in the field, in the night stars and the sand of the sea, in everything which surrounds him and is within him. God is indeed omnipotent, but the task of revealing His presence is the great mission of His people.
When one recites a berachah over food or drink, he in essence is saying, “Master of the Universe, You are hidden behind a cloud; no one sees You. Yet, as I drink this glass of water, I reveal Your presence. The very fact that I can eat, that my body absorbs food, that I can digest, indeed the entire biological process behind food consumption and the creation of food itself, is testimony to Your presence. Through this recognition I am removing the obscuring cloud; I am revealing You.” (Derashot Harav, pp. 12, 40-41)