“For the conductor, on Yedusun” (Tehillim 62:1). “Only for G-d does my soul wait in silence” (Tehillim 62:2). This is what the pasuk says: “Trust in Hashem forever and ever” (Yeshayahu 26:4). HaKadosh Baruch Hu said: Know in Whom you are trusting: in the One who created two worlds with two letters, as it says, “for in Kah, Hashem, is the Rock of [both] worlds” (Yeshayahu 26:4): this world and the World to Come. This world was created with a hei; and so it says, “These are the generations of the heavens and the earth when they were created [behibaram]” (Bereishis 2:4): with a hei He created them. And the World to Come was created with a yud. Therefore, “for in Kah [yud, hei], Hashem, is the Rock of worlds.” And why was this world created with a hei? Just as the hei, when a person brings it out of his mouth, needs no movement of the lips and no work of the tongue, so without toil and without effort HaKadosh Baruch Hu created His world, as it says, “By the word of Hashem the heavens were made” (Tehillim 33:6).