Sunan an-Nasa'i, Volume 4, Book 30, Hadith 3644 (DarusSalam) ⓘ
Abu Habibah At-Ta'i said: "A man made a will leaving some Dinars (to be spent) in the cause of Allah. Abu Ad-Darda' was asked about that, and he narrated that the Prophet said: 'The likeness of the one who frees a slave or gives some charity when he is dying, is that of a man who gives a gift after he has eaten his fill.'"
أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ، قَالَ حَدَّثَنَا مُحَمَّدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ سَمِعْتُ أَبَا إِسْحَاقَ، سَمِعَ أَبَا حَبِيبَةَ الطَّائِيَّ، قَالَ أَوْصَى رَجُلٌ بِدَنَانِيرَ فِي سَبِيلِ اللَّهِ فَسُئِلَ أَبُو الدَّرْدَاءِ فَحَدَّثَ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " مَثَلُ الَّذِي يَعْتِقُ أَوْ يَتَصَدَّقُ عِنْدَ مَوْتِهِ مَثَلُ الَّذِي يُهْدِي بَعْدَ مَا يَشْبَعُ " .
also referenced under: Hadith 3614 (Reference) & Book 30, Hadith 4 (In-Book)