Mishkat al-Masabih 6 Zakat كتاب الزكاة 106

وَعَن أم بجيد قَالَتْ: قُلْتُ يَا رَسُولَ اللَّهِ إِنَّ الْمِسْكِينَ لِيَقِفُ عَلَى بَابِي حَتَّى أَسْتَحْيِيَ فَلَا أَجِدُ فِي بَيْتِي مَا أَدْفَعُ فِي يَدِهِ. فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «ادْفَعِي فِي يَدِهِ وَلَوْ ظِلْفًا مُحْرَقًا» . رَوَاهُ أَحْمَدُ وَأَبُو دَاوُد وَالتِّرْمِذِيّ

Umm Bujaid said she told God’s messenger that a poor man would stand at her door till she was ashamed, for she had nothing in her house to put in his hand, and he replied, “Put something in his hand, even though it should be a burnt hoof.” Ahmad, Abu Dawud and Tirmidhi transmitted it, Tirmidhi saying that this is a hasan sahih tradition.