Is it permissible for a father to register a plot of land and buildings in the names of his male children in exchange for their repayment of a debt he owes, and what is the legitimate Shar'i solution to prevent the land from passing to non-children if they so desire?

It is not permissible to designate male children for land registration to the exclusion of females. This contradicts Islamic law, is unjust, and emulates the practices of the pre-Islamic era of ignorance (Jahiliyyah). The Noble Qur'an states: "For men is a share of what the parents and close relatives leave, and for women is a share of what the parents and close relatives leave, be it little or much - an obligatory share." And the Prophet, peace be upon him, said: "Fear Allah and be just among your children." The correct solution is for the father to sell a portion of his land to his children (males and females) at its real value to settle his debt. If none of them can purchase it, it should be sold to others to settle the debt.