Sunan At-Tirmidhi

Abdur-Rahman bin Bujaid narrated from his grandmother; :Umm Bujaid - and she was one of those who gave the pledge to the Prophet - she said to the Messenger of Allah: ""There is a needy person who stands outside my door, but I cannot find anything to give to him."" So the Messenger of Allah said to her: ""If you do not find anything to give him except a burnt trotter then hand it over to him