Question: In one of his letters, Baal HaSulam wrote that if people discovered the smallest spiritual pleasure, they would agree to cut off their own hands and feet seven times a day just so that they would be able to feel it. Why?
Answer: This is just a figurative expression. He means that the slightest spiritual pleasure cannot be compared to the greatest pleasure in this world because all earthly states are limited.Spiritual pleasure has no limit.
This is not quantitative pleasure that we have in our world. Spiritual delights come in an unlimited amount volume and so they cannot be measured by any methods, frameworks, or units of our world.
We can only feel them after several years of studying the wisdom of Kabbalah.
From the Kabbalah Lesson in Russian 8/28/16