The Torah, “Numbers” 18:15 – 18:16: Every first issue of the womb of any creature, which they present to the Lord, whether of man or beast, shall be yours. However, you shall redeem the firstborn of man, and the firstborn of unclean animals you shall redeem.
Its redemption [shall be performed] from the age of a month, according to the valuation, five shekels of silver, according to the holy shekel, which is twenty gerahs.
All that is first born belongs to the upper level, to the priest (Cohen). A priest is an upper level that is meant to work only with the intention of in order to bestow. Therefore, a person who owns cattle must give the first born of the cattle and his first crop to the priest.
If a person has a first born son, he must redeem him from the priest. Today, we hardly observe this condition because we don’t know for sure who is a priest and who is not. There is no Temple, the land isn’t holy, and we are not in a state of “love your neighbor as yourself.” So these laws are virtually non-existent now.
But there are people who still carry out these conditions. For example, when I was thirty years old, I redeemed myself from the priest. After all, it is said that a person whose parents have not redeemed him must do it himself if possible. He buys five large silver coins, which he weighs and gives to the priest. In this way, he redeems himself from the priest.
But according to the spiritual work, it means that a person lightens the upper part of his soul so that it will work only with the intention of in order to bestow. He gives the priest the strength, which he has earned by himself, in order to receive from the priest the opportunity to acquire his desires and attributes of bestowal.
This is called sanctification. You give the priest money; in other words, your financial strength, and receive from him spiritual strength.
Question: Why is it necessary to redeem precisely the firstborn?
Answer: The fact is that the redemption of the first born is a revelation of a level, and everything that follows is the development of that level.
When you reach the level of “receiving in order to bestow,” it is as if you open it. Then, there is only its complementation, your other secondary attainments. This means that anything that comes after your first born is only the fulfillment of additions to him. The main thing is the first born. Therefore, this is also the reason that he inherits from his parents.
From KabTV’s “Secrets of the Eternal Book” 6/3/15