Is it obligatory to carry out the father's will not to divide a part of his inheritance (an apartment and a car) until after the youngest daughter gets married, especially if this will was not heard directly from the father, and does this will become void?

A will is a significant matter that requires precise attention to its details and wording. In the event of a dispute among heirs, the judiciary is the competent authority to resolve it.

If the father bequeathed that the youngest daughter be married from the estate, this is a bequest to an heir, which is not enforceable unless the rest of the adult, mature heirs consent. As for his bequest to delay the distribution of part of the estate until after his daughter is married, it is not valid; because the estate becomes the property of the heirs upon the death of the testator, and each heir has the right to take possession of their share.

Moreover, a legally valid will is not established by the testimony of one person.