Yahya - bin Ishaq - said:
"Salim said: 'What is Al-Istabraq?' I said: 'A thick type of Ad-Dibaj, and a coarse type of it.' He said: 'I heard 'Abdullah (bin 'Umar) say: "Umar saw a Hullah of Sundus with a man, and he brought it to the Messenger of Allah [SAW] and said: 'Buy this'" and he quoted the Hadith.