Sa'd asked: Messenger of Allah, Umm Sa'd has died; what form of sadaqah is best? He replied: Water (is best). He dug a well and said: It is for Umm Sa'd.
أَنَّهُ قَالَ يَا رَسُولَ اللَّهِ إِنَّ أُمَّ سَعْدٍ مَاتَتْ فَأَىُّ الصَّدَقَةِ أَفْضَلُ قَالَ الْمَاءُ قَالَ فَحَفَرَ بِئْرًا وَقَالَ هَذِهِ لأُمِّ سَعْدٍ