The Zohar, Chapter “VaYigash (Then Judah Approached),” Item 55: Man’s nourishments before the Creator are as hard as the tearing of the Red Sea. This is so because the nourishments of the world are from above, from ZA, from the Masach de Hirik in the middle line. It is so because sons, life, and nourishments do not depend on merit, but depend on luck. And for this reason, man’s nourishments before Him are hard, since it depends on luck, from which the sons, life, and nourishments arrive. This is why the nourishments of the world are hard before Him, for they are not in his possession before he is blessed by luck.
Luck (Mazal) means "flowing" (Nozel) and indicates Upper abundance which comes in drops. It does not pour down as an endless current due to our limitation, our inability to receive more. The Upper One wishes to give us the whole World of Infinity, but He is forced to release the Light for us in drops, to the extent that we are able to perceive it.
This is why it is written that "Man’s nourishments before the Creator are as hard as the tearing of the Red Sea." According to His nature He is “good and does good,” and it is hard for Him to hold back and not give man all the goodness at once. For this reason, it is difficult for the Creator to give only drop by drop.
From the Evening Zohar Lesson 6/7/10