What is the meaning of "Kalalah" mentioned in the two inheritance verses, and does it include the mother and daughter? And why do its rulings differ between the cases mentioned?

The term "Kalalah" is mentioned in two verses of the Quran. The first refers to the inheritance of maternal siblings, and the second to the inheritance of paternal siblings (full or half-siblings from the father's side), in the event that the deceased leaves behind neither a father nor a child. Scholars have unanimously agreed that "Kalalah" refers to "one who has neither a father nor a child."

The word "walad" (child) applies to both male and female offspring. Accordingly, a daughter excludes maternal siblings, while a sister inherits with the daughter by ta'sib (residuary inheritance) after the daughter takes her share, based on the ruling of the Prophet, peace be upon him. This is not a complete exclusion, as Ibn Abbas suggested.

As for the mother, she is not included in the definition of Kalalah. Siblings do not exclude her from inheritance entirely (deprivation), but rather reduce her share from one-third to one-sixth.