The sense of ownership is different in Judaism than it is in general society. We may be accustomed to expressions like,“To each his own” or “A man’s (or woman’s) home is his (or her) castle. In Jewish thought, everything, essentially, belongs to G-d, and this is the reason that, whenever we partake of something, we make a special blessing to thank Hashem (another word for G-d) for letting us use it. The fruit is not simply “ours” because it grows on our tree, is something that has been placed in our possession to be used properly.
Even our children are not really “ours.” Yes, we conceived baby, it grows in its mother’s womb for nine months and is eventually born, but this does not make that child actually ours. A child who is born belongs to Hashem, and this is true of boys and girls, a first child or a sixth child. However, because the first born Egyptians were slain in Egypt when the Jews were enslaved there, the first born Israelites has a special status: Hashem says, “The first issue of every womb among the Israelites is mine (Ex 13:2).” However, a parent can “redeem” their firstborn (i.e. make the child their own), by giving 5 shekels to a Priest (Kohen) when the boy is one month old.
The ceremony marking this occasion is called a “Pidyon haBen” or “Redemption of the first born.” Every first born son who is not a Kohein or does not belong to the tribe of Levi (Aaron’s sons and the tribe of Levi already “belong” to Hashem because of the special tasks they were assigned to perform in the Holy Temple), who experienced a normal delivery (not through Cesarean, because there is a question if this is a “birth” as the Torah explains it), and whose mother did not previously miscarry after 40 days (this might be considered a first birth), can go through this ceremony. Praise Hashem, we had the blessing to have this ceremony for our first born son, and it was quite special, because it was during the festival of Succos, and we had the ceremony and the meal in the Sukka of the shul! The procedure is quite brief, and the liturgy is written in a typical prayer book. The father is asked if he wants to redeem his son for five shekels. He agrees, gives the money to the Kohein and recites a blessing. And then (what else do we do on Jewish occasion) we eat!