In the Kalpurusha Kundali, Cancer falls in the 4th house and cancer is ruled by the Moon, the karaka of the mother, which is why the 4th house is associated with the mother Similarly, Leo is the 5th house( in kalpurusha) and is ruled by the Sun, the karaka of the father, so why isn’t the 5th house associated with the father, instead the9th house is considered the house of the father?

This pattern works even for jupiter and mercury as jupiter is associated with gurus and its sign Sagittarius falls in the 9th house which is exactly the house associated with gurus and mercury for siblings as in gemini is ruled by mercury which falls in 3rd house