Musannaf Ibn Abi Shaybah

Hazrat Abdullah narrates that when Hazrat Umar (may Allah be pleased with him) adopted an opinion and we followed him in that opinion, we found it to be easy. Thus, he was asked about the issue of inheritance regarding the wife and parents, so he gave the wife one-fourth and the mother one-third of the remaining wealth, and ordered that the rest of the wealth be given to the father.