This is known as the human [aspect] of holiness, in that it is focused on purifying the human aspect of the body of the person. The quality of that light in the Divine is like the quality of the human in the physical [structure of] inanimate, plant, animal, and human, in that he acquires sympathy for others. The greatness of that [human] spiritual light is greater than the [lights of the] spiritual inanimate, plant, and animal aspects, in the same measure that the physical human aspect is greater than the physical inanimate, plant, and animal aspects.
Baal HaSulam's Ladder Into the Depths of the Zohar
Baal HaSulam's Introduction to Zohar 49:2