The wisdom behind setting the age of choice at seven years

Question:
Honorable Shaykh, may Allah grant you success, what is the wisdom behind setting the age of choice for a boy at seven years, and likewise the age of seven for a girl when she is handed over to her father? It is known that the authentic hadiths mentioned by the compiler (may Allah have mercy on him) referred to the boy but did not specify his age?

Answer:
Because she said, "I will draw water for you from such-and-such a well," which indicates that he is a person of discernment, for only a person of discernment would go to the well and bring back water. Also, a person of discernment distinguishes between what benefits him and what harms him. Yes, and seven is the general rule; seven years is the general rule, not a fixed, consistent limit, but it is the general rule. Yes.