It is narrated from Muslim bin Yasar: I heard Sayyiduna Abu Hurayrah (may Allah be pleased with him) say that the Messenger of Allah (peace and blessings be upon him) said: "Whoever attributes to me what I did not say, let him prepare his dwelling in Hell. Whoever is given a fatwa without knowledge, its sin is upon the one who gave him the fatwa. And whoever advises his brother on a matter while knowing that the right course lies in something else has betrayed him." The two Shaykhs used all of its narrators as evidence except Amr (bin Abi Nu'aymah), and Bakr bin Amr al-Ma'afiri, one of the imams of Egypt, declared him trustworthy. We are in great need of the wording about verification and care in giving fatwas.