Musannaf Ibn Abi Shayba 9:350

'Abdullah ibn Idris and Waki' narrated to us, from Shu'bah, from Abu 'Awn, from Abu Salih al-Hanafi, that Ibn al-Kawwa' asked 'Ali about combining two sisters [in marriage]. He said: "One verse prohibited them, and another made them lawful, and I will not do it, nor will my family."