Mishkat al-Masabih 6 Zakat كتاب الزكاة 138

وَعَنْ سَعْدِ بْنِ عُبَادَةَ قَالَ: يَا رَسُولَ اللَّهِ إِنَّ أُمَّ سَعْدٍ مَاتَتْ فَأَيُّ الصَّدَقَةِ أَفْضَلُ؟ قَالَ: «الْمَاءُ» . فَحَفَرَ بِئْرًا وَقَالَ: هَذِهِ لأم سعد. رَوَاهُ أَبُو دَاوُد وَالنَّسَائِيّ

Sa‘d b. ‘Ubada told God’s messenger that Umm Sa’d had died and asked him what form of sadaqa was best. When he replied that water was best, he dug a well and said it was for Umm Sa’d. Abu Dawud and Nasa’i transmitted it.