Bina grows and gains strength due to its desire to bestow, to resemble the Creator, Keter, whereas Malchut grows, due to its desire to receive even more Light of Hochma than expands to it from the Creator. After all, it desires to bestow to Him, which means it is supposed to receive from Him more as well! This is what determines how much it bestows.
The fulfillment the Creator initially gives to Malchut, which remains in it in the world of Infinity before it begins to work, is a very basic, “still” level, Nefesh de Nefesh. This was Malchut of Infinity before any restrictions since the creature was unable to experience more. But further on, the creature begins to think about how to restrict itself, how to cover itself with an anti-egoistic screen, and how to come to the Host with it and say: “Give me more Light for I wish to give more to You!”
In fact, the Host only wishes for the creature to receive from Him since it brings Him contentment. And the creature brings forth even stronger desire. “He created me a tiny insect, but I wish to offer Him desires of Infinite magnitude and let Him fulfill them because I wish to delight Him.”
Hence, I bring new desire to Him. In Malchut of Infinity before the restriction, I had only one gram of desire, a still, barely glimmering desire in the Light of Nefesh de Nefesh. In comparison to it, in the end of correction I can bring desire that is 620 (Tarach) times greater and that has the Light of NRNHY (Nefesh, Ruach, Neshama, Haya, Yechida). We have no means to even measure how much more powerful this Light is.
But why am I doing this all? I wish to bring enormous vessels (desires) to the Host so that He may fill them up and rejoice. I delight when He is pleased, while He enjoys when He fulfills and delights me. We fulfill each other. And I needn’t be embarrassed now that I have such gigantic desires, which I am asking Him to fulfill. I am certain that I am doing so solely in order to delight Him, and “He is the joy of my heart.”
From the 3rd part of the Daily Kabbalah Lesson 5/30/2011, Talmud Eser Sefirot