Is refraining from speaking with one's father considered a severance of ties if the father shows favoritism in his treatment of his children and grandchildren?

It is not permissible to abuse parents or turn away from them, for Allah Almighty says: "So do not say to them, 'uff,' and do not repel them but speak to them a noble word." This is considered a prohibited severance of ties in Islamic law.

It is not permissible for a father to discriminate between his children in gifts and endowments, due to the enmity and envy that may arise among them. However, emotional inclination carries no sin.

Likewise, there should be no discrimination between grandchildren, even if justice in giving to them is not obligatory as it is with one's own children.

A father's dereliction of his duty does not permit disobedience to him or abuse of him. His right is great, so one must strive to honor him and treat him well, even if he mistreats.