"Leaf", "Leaves" are the symbol of God's Commandments "growing", being on the "Tree" of God's Will, spiritually healing the spirit, soul and body from unrighteousness, from committing sin and its consequences,
"Leaves" are also the fruits of evangelizing by the Righteous of the Will of God - the beneficial works of men.
Negative Meaning.
"Leaf", "Leaves" is a symbol of various false beliefs, ideologies, created by man to "cover", justify his sinful life.
"Leaf", "Leaves" is a symbol of moral, spiritual barrenness of man, the lack of fruits of a righteous outlook and way of life.