Is the inheritance to be divided equally among the children, or is the male to receive the share of two females, knowing that their grandfather bequeathed to them the share of their mother, who died before him, by saying: "Do not forget the children of so-and-ana on earth"?

Your grandfather's statement, "Do not forget the children of so-and-so on earth," is a metaphor (kinayah), and a bequest can be validly made with it if accompanied by the intention. Your mother does not inherit from her father if she passed away before him. If it is established that your father bequeathed to you an amount equivalent to your mother's inheritance, and this bequest was within the allowable one-third, or if the heirs approved what exceeded it, then it is to be distributed equally between males and females. And if he bequeathed to his relatives, the bequest is for his children, his father's children, his grandfather, and his father's father, with males and females receiving equal shares.