The stronger view in this issue is that the maintenance is obligatory upon the son alone. This is because the son is commanded to show dutifulness to his father more emphatically than the father is commanded to show dutifulness to his son; because the Prophet ﷺ said: “Indeed, the best of what you consume is from your own earnings, and your children are among your earnings.” (1) He also said: “You and your wealth belong to your father.” (2) And he said concerning Fatimah: “She is a part of me.” (3) Thus, a person is a part of his father.
If you say: The verse states, “And upon the heir is a duty like that,” so why do you not base it on the shares of inheritance? We reply: This concerns the nursing of a child, not maintenance.
His statement: “If a person has a poor son and a wealthy brother, neither of them is responsible for his maintenance”: the brother is not responsible for his maintenance, because the brother does not inherit from him, being excluded by the son; nor
(1) Reported by Imam Ahmad (6:41); Ibn Majah, al-Tijarat (Commerce), chapter: “What a man may take from his son’s wealth” (2290); al-Tirmidhi, al-Ahkam (Legal Rulings), chapter: “What has been reported concerning a father taking from his son’s wealth” (1358); and al-Nasai, al-Buyu' (Sales), chapter: “Encouragement to earn” (4450; 7:240), on the authority of Aisha, may Allah be pleased with her. Al-Tirmidhi said: “Hasan sahih (fair and authentic).” It was also authenticated by Ibn Hibban (4261). See al-Talkhis (1665) and al-Irwa (1626).
(2) Reported by Ibn Majah, al-Tijarat (Commerce), chapter: “What a man may take from his son’s wealth” (2291), on the authority of Jabir, may Allah be pleased with him. Al-Busiri authenticated it according to al-Bukhari’s criteria. Ibn Hibban also authenticated it in al-Ihsan (410), on the authority of Aisha, may Allah be pleased with her. It was also reported by Imam Ahmad (2:179, 204, 214); Abu Dawud, al-Buyu' (Sales), chapter: “A man eating from his son’s wealth” (3530); and Ibn Majah, al-Tijarat (Commerce), chapter: “What a man may take from his son’s wealth” (2292), through Amr ibn Shuayb, from his father, from his grandfather. Its chain of transmission was graded hasan (sound) in al-Irwa (3:325).
(3) Reported by al-Bukhari, al-Manaqib (Virtues), chapter: “The virtues of the Prophet’s relatives” (3714), and Muslim, al-Fada'il (Virtues), chapter: “Among the virtues of Fatimah, the Prophet’s daughter” (2449), on the authority of al-Miswar ibn Makhramah, may Allah be pleased with him.