The Hasidic teaching is based on the Kabbalah which is based on the oral tradition. This goes back at least to Moses if not Abraham if not Adam. Of course they develop this over the years. The idea that the letters fit into the Star of David could not go back before David. This teaching really does not make sense until a person has been a christian for 40 years. If you were born a Christian then you understand when you are 40. For me I did not get saved until my 20's so it was in my 60's that I began my study what the Hasidic Rabbi's were teaching. They are the ones that do not trim the beard. They let their face hair grow wild.Never once mentioned anything regarding Hebrew letters...
The idea that they want to add to the teachings of Moses is something I have problems with. When I ask them about it they do not say anything so they do not give me an answer. They have 613 commandments they follow and Jesus said it was enough to follow the teachings of Moses and do not add to that.
"So practice and observe everything they tell you. But do not do what they do, for they do not practice what they preach. They tie up heavy, burdensome loads and lay them on men’s shoulders, but they themselves are not willing to lift a finger to move them." (Matthew 23:4)