Is the mother absolutely more entitled to custody than the father?

Question:
He says: Honorable Shaykh, may Allah grant you success, is the mother absolutely more entitled to custody than the father, or is it said that the one more entitled to custody is the one who is most suitable, so the mother might be less suitable?

Answer:
If there is a barrier in the father that prevents him from having custody, then the custody belongs to the mother in all cases, unless there is a barrier in the mother that prevents her, in which case it transfers to the father, because it is an obligatory right upon her, not a right for her; it is an obligatory right upon her for the sake of the child in her custody.