Sayyiduna Sa'd bin Ubadah (may Allah be pleased with him) said: I said: "O Messenger of Allah, the mother of Sa'd has died and she made no bequest; shall I give charity on her behalf?" He (peace and blessings be upon him) said: "Yes."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5363