Ata, Mujahid and Ikrimah (may Allah have mercy on them) said: For each poor person there should be a shirt, a waist-wrapper or a cloak. I said to Khusayf (may Allah have mercy on him): What if he is well-off? He said: Whichever he does, he has done well. If he finds none of these, let him fast three days. In the recitation of Ubayy (may Allah be pleased with him), he is to fast consecutively. In the narration of Ibn Jurayj (may Allah have mercy on him) from Ata (may Allah have mercy on him), (it is) that this is in the expiation for an oath: one mudd each and one garment each.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 19982
Ibn al-Zubayr al-Hanzali narrates from his father that a man asked Sayyiduna Imran bin Husayn (may Allah be pleased with him) about a person who had sworn that he would not pray in the mosque of his people. Sayyiduna Imran bin Husayn (may Allah be pleased with him) said: I heard the Prophet (peace and blessings be upon him) say: "There is no vow in disobedience to Allah, and its expiation is the expiation of an oath." I said: O Abu Nujayd! Our companion is not well-off, so with what should he give the expiation? He said: "If some people went to one of the governors and he clothed each of them with a cap, people would say: He has clothed them." And it is mentioned from Sayyiduna Salman (may Allah be pleased with him) that the best garment is the tubban (short trousers).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 19983