Nothing can be transformed from one thing to another unless it first loses its original identity. Thus, for example, before an egg can become a chicken it must completely cease to be an egg. Each thing must be nullified before it can be something else. It must be brought to the level of ayin (divine nothingness). Only then can it become something else and this is how all miracles involving a change in the laws of nature come about. Each thing must first be elevated to the emanation known as I am, nothingness. Influence them comes from that emanation to produce the miracle...
The Essential Kabbalah Page 71
Think of yourself as ayin and forget yourself totally. Then you can transcend time, rising to the world of thought, where all is equal: life and death, ocean and dry land. This is not the case when you are attached to the material nature of the world if you think of yourself as yesh, as something, God cannot be clothed in you, for God is infinite, and no vessel can contain God-unless you think of yourself as Ayin.
Adapted from the teachings of the Maggid of Mezeritch (Rabbi Dov Ber)
Rabbi Levi Yitzchak of Berditchev
"When man nullifies his ego completely and attaches his thoughts to ayin, then a new sustenance can flow into all worlds.… A person must be so in honor of God that his ego is totally nullified. Only then can he attach himself to ayin. [Divine] sustenance, filled with all goodness, then flows to all worlds."
"When a person gazes at an object, he elevates it into his thought. If his thought is that attached to the realm of supernal thought, he can elevate it to the realm of supernal thought. From there it can be elevated to the level of nothingness, where the object becomes absolute nothingness this person and then lower it once more to the level of thought which is something to us. At the end of all levels he can transform it into gold."
פִּילוֹסוֹפִי אֶחָד שָׁאַל אֶת רַבָּן גַּמְלִיאֵל, אֲמַר לֵיהּ צַיָּר גָּדוֹל הוּא אֱלֹהֵיכֶם, אֶלָּא שֶׁמָּצָא סַמְּמָנִים טוֹבִים שֶׁסִּיְּעוּ אוֹתוֹ, תֹּהוּ, וָבֹהוּ, וְחשֶׁךְ, וְרוּחַ, וּמַיִם, וּתְהוֹמוֹת. ...
A philosopher once questioned Rabban Gamliel and said to him, ''Your God is only a great artist because God found great materials that helped him: tohu and vohu, darkness, spirit, water, and the depths."...