the sister of the paternal grandmother, it indicates her priority, and that is because she is related through an agnate (asaba) while being equal to the other in childbearing, so it is necessary to prioritize her, like prioritizing the sister through the father over the sister through the mother. The mother was only prioritized over the father because she is a female who performs custody by herself, so likewise is the paternal grandmother; she is a female who performs it by herself, so she is prioritized for the reason we mentioned.
1403 - Issue; He said: (And the sister through the father is more entitled than the sister through the mother, and more entitled than the maternal aunt).
The general summary of this is that if there is no one who is entitled to custody, from among the fathers and mothers even if they are distant, it transfers to the sisters, and they are prioritized over all other relatives, such as maternal aunts, paternal aunts, and others; because they share in lineage and are prioritized in inheritance. Furthermore, the paternal and maternal aunts are only related through the brotherhood of fathers and mothers, and they have no inheritance share when there is an heir with a fixed share or an agnate. Thus, one who is related to the person under custody and inherits from them is closer and more compassionate, and therefore more entitled. The most entitled of the sisters is the one who is related through both parents, due to the strength of her kinship, [then the one who is related through the father], then the one who is related through the mother. Ahmad stated this, and it is the apparent position of the Shafi'i school. Abu Hanifah said: The sister through the mother is more entitled than the sister through the father. This is also the view of al-Muzani and Ibn Surayj, because she is related through the mother, so she is prioritized over one related through the father, like the maternal grandmother compared to the paternal grandmother. Ibn Surayj said: The maternal aunt is prioritized over the sister through the father for the same reason. There are two narrations from Abu Hanifah regarding this. Our argument is that the sister through the father is stronger in inheritance, so she is prioritized, like the sister through both parents. Her strength is not hidden, for she is placed in the position of the sister through both parents in her absence, and she becomes an agnate with the daughters, and shares with the grandfather. What they mentioned regarding the connection (idla') is not binding, because the sister is related in her own right, as they were created from the same fluid, and she has agnation (ta'sib), so she is more entitled. And Allah knows best.
(6) In A, M: "the one who (allati)". (1) Omitted from: B. (2) Omitted from: B. (3) In B, M: "and for them both (wa-lahuma)".