Musannaf Ibn Abi Shayba 26:26

Ibn ‘Uyaynah narrated to us, from Mansur, from Ibrahim, from ‘Alqamah, from ‘Abdullah, that he said: ‘Umar, if he traveled a path and we traveled it, we would find it easy. He was asked about a wife and two parents, and he said: For the wife is a fourth, and for the mother is a third of what remains, and what remains is for the father.