What does Islam want from parents in their interaction with their children, in accordance with equity and justice?
The fundamental principle in Islam is justice, and equity is a manifestation of justice. Such justice may be exemplified in matters of affection with respect to the children. This is what is reported from the Prophet: that he saw a man kissing one of his sons, and so he said to him, “Kiss the other one, so he may not feel anything against his brother or his father.”
Equity is a fundamental principle in parents’ care of their children, but sometimes we need to stay away from equality in justice, when one child is better in religion than the other; is better in his studies or morals; or is more obedient. In this case, we prefer him to his brother in order to influence that latter brother to be like him, so that he could receive the same treatment. In other words, we create a situation of competition, which needs some wisdom in its application, so the child does not assume that the father loves his brother more.
Grand Ayatollah Sayyed Muhammad Hussein Fadlullah.