"It is well known that the Sharī'ah has come to achieve best interests (maṣāliḥ) and perfect them, and to eliminate detriments (mafāsid) and minimize them as much as possible."
— Shaykh al-Islām Ibn Taymiyyah (d. 728 AH)

"Most of the corruption in children has come from their parents, due to their neglect of them and failure to teach them the obligations and practices of religion. They neglected them when they were young, so they did not benefit themselves, nor did they bring benefit to their parents when they grew older."
"The mother's scent, bed, and lap are better for him than the father until he matures and can choose for himself."
"Its basis is on the compassion that ensures continuous care, as a non-discerning child needs someone compassionate to look after them."
"The truth is that custody is a form of guardianship, and it should only be held by the one most suited to it, with suitability referring to the care of the child's needs. Islamic law does not prioritize one person over another solely based on kinship but prioritizes the most deserving, most capable, and best suited."
— 'Abd Allah Aal Bassām (d. 1423 AH)
"Every duty requires strength and trustworthiness, as Allah says: {Indeed, the best one you can hire is the strong and the trustworthy.} If one cannot fulfill the custody responsibilities, they lack strength; if they are capable yet fail to perform their duties, they lack trustworthiness."
"Anyone entitled to custody who does not have sufficiency, does not provide a secure environment, or cannot be trusted, does not have the right to custody. The child's interest should be prioritized, seeking the most competent and secure caretaker, for a father could neglect his child."
"Allah has instilled in the children of Adam an inherent tendency for interaction between two similar things. The greater the similarity, the more complete the interaction in manners and traits… Similarity and resemblance in outward matters also lead to a hidden and gradual similarity in inward aspects."