Is it permissible for a father to register the apartment and land he bought from the savings of his trade—which he began after marrying his second wife—to only his children from her, and then they inherit with their siblings from the first wife in the old house and land? What is the ruling of Sharia on this?

A father must be just among his children in granting gifts, and it is not permissible to single out some of them without a legitimate reason. A wife helping her husband in trade is not a legitimate reason.

Singling out a child for a need or similar reason is a matter of scholarly disagreement. Some scholars have prohibited it absolutely, while others have permitted it if the designation is for a meaningful reason, such as need, disability, large family, engagement in seeking knowledge, or if the deprived child is a transgressor.

Registering property in the name of the donee does not constitute a valid gift unless there is possession and disposal. If the donor or donee dies before possession, the gift becomes void. Possession is achieved by relinquishment (takhliyah). This type of gift is considered a will and is not valid for an heir unless all heirs approve it.