Praise be to Allah.
One of the matters on which there is scholarly consensus is that the woman is more entitled to custody of the child so long as he has not reached the age of discernment, as the child at that stage needs the kind of compassion and care that only women can give, but this right is forfeited if the woman remarries, because she will be distracted by her new husband from taking care of her child, and because there is a conflict of interest between the child and the new husband. Ibn al-Mundhir (may Allaah have mercy on him) narrated that there was scholarly consensus that the mother’s right to custody is forfeited if she remarries.
See: al-Kaafi by Ibn ‘Abd al-Barr (1/296); al-Mughni (8/194).
This is indicated by the hadeeth of ‘Abd-Allaah ibn ‘Amr (may Allaah be pleased with him) according to which a woman said: O Messenger of Allaah, my womb was a vessel for this son of mine, and my breasts gave him to drink, and my lap was a refuge for him, but his father has divorced me and he wants to take him away from me. The Messenger of Allaah (peace and blessings of Allaah be upon him) said to her: “You have more right to him so long as you do not remarry.” Narrated by Ahmad (6707) and Abu Dawood (2276); classed as hasan by al-Albaani in Saheeh Abi Dawood, and classed as saheeh by Ibn Katheer in Irshaad al-Faqeeh (2/250).
Maintenance of children is obligatory upon the father according to scholarly consensus, whether he keeps his wife or divorces her, and whether the wife is poor or rich. So she is not obliged to spend on the children if the father is around.
If the children are in the custody of a divorced woman, then their father must support them, and the mother who has custody of a child who is still breastfeeding has the right to ask for payment for nursing the child.
Maintenance of children includes accommodation, food, drink, clothing and education, and everything that the child needs, and is to be based on what is reasonable, paying attention to the husband’s situation, because Allaah says (interpretation of the meaning):
“Let the rich man spend according to his means; and the man whose resources are restricted, let him spend according to what Allaah has given him. Allaah puts no burden on any person beyond what He has given him. Allaah will grant after hardship, ease”
This varies from one country to another and from one person to another.
If the husband is rich then he must spend according to his wealth, and if he is poor or of moderate means, then he must also spend according to his means. If the parents agree upon a specific amount on money, whether it is great or small, then that is up to them. But in the case of dispute, the one who should decide about that is the qaadi (judge).
It is permissible for a divorced woman to ask her ex-husband for payment for breastfeeding the child, according to scholarly consensus.
Ibn Qudaamah (may Allaah have mercy on him) said in al-Mughni: (The expenses for) breastfeeding the child are to be borne by the father only, and he has no right to force the mother to breastfeed him if she is divorced, and we know of no difference of opinion concerning that. End quote from al-Mughni (11/430).
He also said: If the mother asks for payment at the usual rate for breastfeeding him, she is more entitled to that, whether the father finds someone else to breastfeed him for free or not. Al-Mughni (11/431).
Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) said: With regard to payment for breastfeeding, she is entitled to that according to scholarly consensus, as Allaah says (interpretation of the meaning):
“Then if they give suck to the children for you, give them their due payment”
End quote from al-Fataawa al-Kubra (3/347).
With regard to custody – as defined by a number of scholars – it means taking care of the one who has not reached the age of discernment and cannot live independently, and raising him in accordance with his best interests and protecting him from anything that may harm him. Rawdat al-Taalibeen (9/98). What is meant is taking care of the small child and looking after him. So the main issue of custody is taking care of the interests of the child. Hence if the father refuses to undertake this duty towards the child, which includes maintenance, then he is sinning, and forfeits his right to custody. It says in al-Rawdah al-Murbi’: The child should not stay with one who does not protect him and take care of him, because that is contrary to the purpose of custody. Al-Rawd al-Murbi’ (3/251).
Ibn Qudaamah al-Maqdisi said: Custody is aimed at looking after the child, so it should not be given in a way that will be detrimental to his welfare and his religious commitment. Al-Mughni (8/190).
Ibn al-Qayyim said: If we show precedence to one of the parents, we must pay attention to how he looks after the child. Hence Maalik and al-Layth said: If the mother is not in a safe place or she is not of good character, then the father has the right to take the child from her. Similarly in the well known report from him, Imam Ahmad said that it depends on his ability to take care of the child. If he is careless or unable to do that, or is not of good character, or he is immorall and the mother is different from him, then she undoubtedly has more right to take the daughter. Our Shaykh said: If one of the parents fails to educate the boy and raise him in accordance with Islamic teachings, then he is sinning and has no guardianship (wilaayah) over him. Anyone who does not do his duties as a guardian has no guardianship. He should either be dismissed as the guardian and replaced by someone who will do what is required, or someone else should be appointed with him who will do what is required along with him, because the aim is to obey Allaah and His Messenger according to one’s ability. … If the father marries a woman who does not take care of his daughter, and her mother is better able to take care of her than this co-wife, then custody should definitely be given to the mother. Zaad al-Ma’aad (5/424).
Shaykh ‘Abd al-Rahmaan al-Sa’di said: But if one of them neglects their duties with regard to custody and care of the child, then he forfeits his guardianship and the other should be appointed instead. Al-Fataawa al-Sa’diyyah (p. 535).
Based on this, if the father refuses to spend on his children’s maintenance, he forfeits the right to custody, even if his refusal is aimed at hurting the mother. This indicates that he is not to be trusted to take care of his children’s interests. The mother has the right to ask him in court for maintenance of his children.
And Allaah knows best.