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."

أَخْبَرَنَا الْحُسَيْنُ بْنُ عِيسَى، قَالَ أَنْبَأَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ سَعْدًا، سَأَلَ النَّبِيَّ ﷺ إِنَّ أُمِّي مَاتَتْ وَلَمْ تُوصِ أَفَأَتَصَدَّقُ عَنْهَا قَالَ " نَعَمْ ".