Saad bin Ubada's mother passed away while he was absent. He said, "Messenger of Allah, my mother has died while I was away from her. Will it benefit her if I give something in charity on her behalf?"The Prophet ﷺ replied, "Yes."Saad said, "Then I call you to witness that my orchard, al-Mikhraf, is given as charity on her behalf."
أن سعد بن عبادة توفيت أمه وهو غائب عنها، فقال: يا رسول الله، إن أمي توفيت وأنا غائب عنها. أينفعها شيء إن تصدقت به عنها؟ قال: نعم. قال: فإني أشهدك أن حائطي المخراف صدقة عليها.
Bukhari related it in the Book of Wills (2756) from Muhammad, who said, Makhlad bin Yazid told us, Ibn Jurayj told us, he said, Yaala informed me that he heard Ikrima say, Ibn Abbas told us, saying (he then mentioned it). Muhammad here is Ibn Salam, as in the narration of Abu Dharr and others, and Yaala is Ibn Muslim, whom Abdul-Razzaq named in his narration from Ibn Jurayj on his authority.The mother of Saad bin Ubada was Amra bint Masud. Ibn Saad mentioned that she embraced Islam and gave the pledge of allegiance, and that she died in the year five, while the Prophet ﷺ was on the expedition of Dumat Jandal, with her son Saad bin Ubada accompanying him.Bukhari also related it (2770) through another route, from Amr bin Dinar, from Ikrima, from Ibn Abbas, that a man said to the Messenger of Allah ﷺ, "My mother has died..." The unnamed man here is Saad bin Ubada, as mentioned before and as will come in the hadith after this one.As for al-mikhraf, it is a garden of palm trees, and the term applies both to the palm trees themselves and to the fresh dates.