קבלה על חולין 120:63

123 ּBut the matter is, that the soul in its existence and root is very very great, but in order for it to come into this body - behold the Holy One blessed is He diminished its light and strength, and left for it only that measure which is appropriate for the body in this world. And behold it is in that time period like the moon where it says to it (Chullin 60b), " Go and diminish yourself", and in the future (Isaiah 30:26), "And the light of the moon will be like the light of the sun". And behold in its hand is goodness - to elevate from elevation to elevation until he highest strength, according to the perfection of its actions. And behold according to the diminution of power which was given to it in this world, it stands closing and closed within the cloudy body throughout the days of its service, to be tested and examined with the trials of the evil inclination, for it is for this that it was placed within man, and like their saying may their memory be for a blessing, (Zohar section 1, 106b) "The evil inclination was not made other than to test man with it". And according to the aptitude of its actions - so does it merit for itself elevation, to rise from level to level. And behold in the time of the reward then the events of all of the souls activates them, and elevates them according to their actions, and in this level of elevation will they return and refine their bodies in the time of the resurrection, and they will enjoy the plethora of peace forever, as we explained above: