Question: There is a rumor that a person can start studying Kabbalah only after the age of 40. Is that correct?
A person who has reached the level of Bina obtains the absolute property of bestowal where he can reveal the entire enormous Light of Hochma that governs the entire universe. Therefore, the wisdom of Kabbalah has two parts: before the level of Bina and above it. Everyone is able to study up to the level of Bina. However, above it, only those who are capable can continue and rise further.
The level of Bina is called “the age of 40.” Therefore, the only people who can “study Kabbalah”—meaning, receive the Light of Hochma—are those who have reached the level of Bina, which is defined by the number 40. However, this has nothing to do with the biological age of a person.
As proof, there is the example,of famous Kabbalists who died at a young age without reaching the age of 40, such as the ARI, Rabbi Nachman from Breslav, and others. Obviously, they began studying Kabbalah long before they were 40 years old.
There was also a ban for unmarried people to study Kabbalah. It was considered that a person with a family was more stable and balanced, and as a result, they would be more suitable for the study. However, during those times, people used to marry when they were 16 to 17 years old.
From the Israeli Radio Program 103FM 2/28/16