Mishkat al-Masabih 6 Zakat كتاب الزكاة 98

وَعَنْ أَبِي الدَّرْدَاءِ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَثَلُ الَّذِي يَتَصَدَّقُ عِنْدَ مَوْتِهِ أَوْ يُعْتِقُ كَالَّذِي يُهْدِي إِذَا شَبِعَ» . رَوَاهُ أَحْمَدُ وَالنَّسَائِيُّ والدارمي وَالتِّرْمِذِيّ وَصحح

Abud Darda’ reported God’s messenger as saying, “One who gives sadaqa or who frees a slave at the time of his death is like one who gives gifts when he has more than enough.” Ahmad, Nasa’i, Darimi and Tirmidhi transmitted it, and Tirmidhi said it is sahih.