Is it permissible for a father to write over his property to his only son, given that he has seven married daughters who approve of this?

If a father writes his properties in the name of his son, stipulating that the son owns them after his death, this is not Islamically valid because it is a bequest to an heir. A bequest to an heir is not enforceable unless approved by the adult, mature heirs.

However, if he transfers ownership to the son now and relinquishes control of it, this is permissible, provided that he gives his daughters an equal share, or they willingly waive their right while being adult and mature, due to the obligation of equitable distribution among children in gifts.