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