Is the father's division of a plot of land among his children, whereby he gives his married daughters a larger portion that includes two houses, while giving his son a smaller, barren piece of land, considered an unfair division that makes the son's share unlawful? And is the father's building a house for his son from his own money unlawful if the daughters' husbands object to it? And is the son's refusal to sponsor his sister's son for studying abroad, due to his financial inability, considered a failure to show kindness to relatives?

If the father divides the land as an inheritance, this division is invalid. However, if it is a gift, it is valid on the condition of justice among the children, meaning that the value of what each of them is given must be equal, in accordance with the Prophet’s (peace and blessings be upon him) saying: "Be just among your children in giving, for if I were to prefer anyone, I would prefer women."

If he is just in his gift, it is effective. If he is not just, he must return what he favored some with, or complete the share of the others. Otherwise, the gift is invalid, and it is not permissible to build on the land in this situation. It is not permissible for the father to allocate something from the wealth to one child unless he gives an equivalent to the rest. You are not obliged to bear the educational expenses of your sister's son. It is advised to reach a solution that satisfies everyone and does not contravene Islamic law.