Mishkat al-Masabih 1880

A client of ‘Uthman said that Umm Salama was presented with a piece of meat, and because the Prophet liked meat she told the servant to put it in the house as the Prophet might perhaps eat it. She put it in the window ledge in the house. A beggar came and stood at the door and said, “Give alms, may God bless you," and when they replied, “God bless you,"* the beggar went away. Then the Prophet entered and asked Umm Salama whether she had anything for him to eat. She replied that she had, and told the servant to go and bring God's messenger that meat, but when she went she found only a piece of flint in the window ledge. The Prophet then said, “That meat changed into flint because you did not give it to the beggar." Baihaqi transmitted it in Dalail an-nubuwa. * A pious remark used to indicate that there is no intention of giving anything. The most common phrase in such circumstances is Allah karim (God is generous).