Musannaf Ibn Abi Shayba 30:120

Ibn ‘Ulayyah narrated to us, from Abu Raja’, from al-Hasan, regarding [the verse]: "Reclining on green cushions (rafraf)." He said: "The 'busut' (carpets/spreads). The people of the Jahiliyyah used to say that it is the 'busut'."