Kabbalah do Izajasza 26:4

"And Elohim spoke to Moses and said to him, 'I am Hashem and I appeared to Abraham, to Isaac, and to Jacob, by the name of El Shadai...'" (Shemot 6:2-3). Rabbi Abba opened the discussion saying, "Trust in Hashem forever (Heb. עֲדֵי עַד), for Yah Hashem is an everlasting rock" (Isaiah 26:4). "Trust in Hashem" means that all the people of the world have to strengthen themselves in the Holy One, blessed be He, and trust in Him.

Therefore "Trust in Hashem forever" (Isaiah 26:4). For from there up, the place is covered and hidden, as none can conceive it. It is a place from which the worlds emerge and are formed. This is the meaning of, "For Yah Hashem is an everlasting rock." This place is hidden and concealed. Therefore, "Trust in Hashem forever (Heb. adei ad)," that up to here, everyone is permitted to observe. From here and further no one is permitted to observe because it is concealed from everyone. And what is Yah, Yud Hei Vav Hei, whence all the worlds were formed, and no one is able to understand that place, in order to conceive anything.

What is the reason? Since the world endures by His Holy Name. This is the meaning of, "For Yah Hashem is an everlasting (lit. 'worlds') rock (Heb. tzur)" (Isaiah 26:4), the former (Heb. צַיָּיר) of worlds. For by two letters were the worlds created, this world and the World to Come. This world was created with Judgment and is maintained on Judgment. This is the meaning of, "In the beginning Elohim created" (Beresheet 1:1). The reason is so that people would conduct themselves according to judgment (law) and would not digress from the path.