Narrated Ibn 'Abbas: The custom (in old days) was that the property of the deceased would be inherited by his offspring; as for the parents (of the deceased), they would inherit by the will of the deceased. Then Allah cancelled from that custom whatever He wished and fixed for the male double the amount inherited by the female, and for each parent a sixth (of the whole legacy) and for the wife an eighth or a fourth and for the husband a half or a fourth.
This hadith teaches us about justice and fairness as it ensures that everyone receives what is due to them according to Islamic law. It also encourages us not only take care of our own families but also those of our relatives who may be left behind after we pass away by leaving something for them through our will if we wish so.