What is the ruling on leaving a young girl with her non-Muslim mother, who does not object to teaching her the Qur’an and prayer, but strongly refuses the hijab? And what is the ruling on divorcing her and leaving the girl with her in order to dedicate oneself to seeking knowledge and da‘wah abroad for 5-6 years?

A student of knowledge should not leave his wife and daughter. Rather, he should take care of his family; for Allah Almighty says: (And warn your closest kindred). And in the Hadith: "Your mother, then your mother, then your mother, then your father, then the nearest, then the nearest." With the availability of communication tools, it has become easy for a student of knowledge to bring his family with him, or to seek knowledge remotely via the internet, or summer courses, or recorded scientific series. The important thing is determination and patience in seeking knowledge, and combining it with showing kindness to one's family. It is a great sin for a person to withhold sustenance from those he is responsible for. Travel is no longer necessary for seeking knowledge as it was in the past; rather, one can combine learning with making his family happy. And beware of divorce and separation from children, especially with the many alternatives available for seeking knowledge.