ENOfficial
It was narrated from Ibn 'Abbas that Sa'd asked the Prophet: "My mother died and did not leave a will; shall I give charity on her behalf?" He said: "Yes."
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا الْحُسَيْنُ بْنُ عِيسَى، قَالَ أَنْبَأَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ سَعْدًا، سَأَلَ النَّبِيَّ صلى الله عليه وسلم إِنَّ أُمِّي مَاتَتْ وَلَمْ تُوصِ أَفَأَتَصَدَّقُ عَنْهَا قَالَ " نَعَمْ ".
sunnah.com