Sa'id bin Amr bin Shurahbil narrates from his father, from his grandfather; he said: Sayyiduna Sa'd bin Ubadah (may Allah be pleased with him) had gone out with the Prophet (peace and blessings be upon him) on one of his expeditions when the time of death came to his mother in Madinah. Someone said to her: "Make a bequest." She said: "What shall I make a bequest of? The wealth is only Sa'd's wealth." So she died before Sa'd (may Allah be pleased with him) returned. When Sa'd (may Allah be pleased with him) returned, this was mentioned to him. Sa'd (may Allah be pleased with him) said: "O Messenger of Allah, will it benefit her if I give charity on her behalf?" The Prophet (peace and blessings be upon him) said: "Yes." Sa'd (may Allah be pleased with him) said: "Such-and-such garden is charity on her behalf," and he named a garden.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5502