Musannaf Ibn Abi Shayba 19:252

Abu Bakr narrated to us, he said: Abd al-Rahim narrated to us, from Isma'il, from al-Hasan, he said: If a man commits slander in the winter, he shall not be dressed in the clothes of summer, but he shall be lashed in the clothes in which he committed the slander. If he commits slander in the summer, he shall not be dressed in the clothes of winter; he shall be lashed in that which he committed the slander in.