What is the Shar'i (Islamic legal) and legal position regarding a man who divorced his wife through Khul' (dissolution of marriage at the wife's instance), and fears that he will be stripped of the custody of his two daughters whom he raised after his separation from his wife?

When a husband and wife separate, custody of the children belongs to the mother unless there is a valid impediment, in order to safeguard the best interests of the minors. If the mother's right to custody is forfeited, custody transfers to the maternal grandmother according to the majority of scholars, with the clarification that when custody transfers to the father, it is stipulated that there must be a woman to undertake the care. The father's right to see his children is not forfeited by the mother having custody. In cases of dispute, the Sharia court decides on the matter of custody.